tbqh, playing cb after c4 really looks fine for white and will help him get his queenside untangled

This is a big red flag imo. I'm nowhere near as good as either player in this game, but if I had a nickle for every time I've said something like this to myself while playing a game and than made a truly terrible move, I would own one of those sets made of diamonds and onyx.

I'm just going with my initial line of analysis. I have to be verya careful about black playing c4 and b3 trapping my bishop on b1 and also trapping my rook on a1.

The position looks about equal to me. Not much is really happening. After a logical sequence of moves all the rooks are exchanged on the d-file followed by a draw.

He moved Bg5, i more or less expected that move after i sent my last one, but didn't write about it. In fact, i'm not sure if it is much to write home about. Let's see what are the implications:
- the direct c5-c4 isn't any good anymore, he'll take on b4 and if i take back i lose a pawn on f6.
- if his knight were already on say f1, there would be a positional threat to eliminate the defender of d5 via Bxf6, occupy d5 and play with good knight vs bad bishop. As a former Najdorf player, i'm very familiar with that. Fortunately his knight is a long way from d5 as result of my development advantage, so idon't have to worry about that too much now.
- he'll be looking to complete development smoothly and then try to pursue his own positional goals. I should be looking to maintain my slight initiative.

So what are my options? The first thing to consider is the forced line 16. ...b3 17. Bd3 c4 18. Bf1/e2. I think this is just bad for me, it makes my bishop better but the pawn on c4 is very easy to attack by white's minor pieces and i just don't think i get anything in return, maybe c5 square for knight or bishop but i'll probably be to tied up by the defence of c4 to really maneuvre pieces there.

My favourite idea at the moment is to improve the Nf6 and gain time by offering to exchange my bad bishop. So 16. ...Ne8 is a natural candidate. I'll have to check if 17. Bxe7 Qxe7 18. Rd5 is a reason to worry, and if not i can go on to check fun lines like 17. Be3 Nd6 18. b3 c4!?
Other typical ideas might be h6 with the plan of 17. Bh4 Nh7, or simply 16. ...Rd8. But i'm going to play concrete chess here and try to avoid natural moves that don't really pertain to my queenside plans.
So much for now, move will follow later today.

I agree with you. The b1 knight gets the c3 square and both sides have weak pawns on the queenside. If white really wants to play the c4/b3 idea, I think b3 first followed by c4 makes more sense.

I have decided that this is the move that does most for my queenside initiative. It reactivates the c5-c4 idea by overprotecting the pawn on b4. A sample line i analysed runs:
17. Nd2 c4 18. cxb4 Rxb4 19. Qc3 Rfb8 20. b3 h6 and now on Bh4 i already have the Nxe4 shot while 21. Bxf6 Bxf6 22. bxc4 Bg5! looks also fine for black. 20. Rb1 h6 doesn't trouble me too much either.
The former candidate 16....Ne8 now looks a bit slow to me. After 17. Bxe7 Qxe7 18. Nd2 Nd6 the knights step on each other's toes. And i'm also going to play for more than equality here, not because i think i'm better at this point but the Rb8 line looks like more fun.

Feeling pretty lost here (ideas wise). But then again, I've been looking for an advantage where there is none. I have to cut my losses and just develop pieces. Af first I really didnt want to play 17. Nd2 because of 17...c4 threatening b3 and trapping the light squared bishop and alos trapping the rook on a1. In the event he does play 17...b4 I'll play 18.Re1 to play Bd1 to e2. I give black the d file for his rooks but I need to get pieces developed without them tripping over each other. My knight likewise is going to have a trip to d5 via Nd2-f1-e3-d5

I don't see much reason to deviate from the chosen plan here. I should have considered Nc4 on the previous move though.

I'm not sure this ....c4 ....b3 idea is going to work out.

White will seem to be wasting time playing Re1, Bd1, and eventually Be2. But, actually he'll be putting his rook back where it belongs and his e2 bishop and d2 knight will now be tying Black down to the defense of a very weak c4 pawn.

Black's considerable extra space on the queenside may not be as usefull with the pawn structure fixed.

Black's potential knight maneouver Nd7-c5-d3 will probably just end with Bxd3 and an even more vulnerable pawn on d3.

After White's planned Re1 move, I think Black doesn't need to be in a hurry to play b3, but Rfd8 looks more unpleasant since Bd1 Rd3 looks good for Black and if Rad1, then b3 kills the Bishop again.

I think I can make this move work tactically for example:

18. cxb4 Nc6 19. Nxc4 Nd4 20. Qd3 Rxb4 21. b3 and black has an active position but white has the extra pawn with opportunities of getting active with the kight getting to d5.

18. cxb4 Rxb4 19. Bxf6 Bxf6 20. Qc3 Rfb8 21. b3 Bg5 22. Nxc4 Nxc4 23. Bd3 Rxb3 24. Qxc4 Qxc4 25. Bxc4 R3b6 26. Rd7 and I hope I'm not fantasizing to much in this variation and that it is objective. But the end game looks dominating for white.

so far as expected. Probably a critical point of the game is approaching fast, let's see what he does now.

I much prefer Black now and have done for a little while. He isn't cramped and doesn't have problems finding something to do on the queenside and White has no kingside pressure. That should be all you can ask for in the Spanish.

Black will have more activity, but a pawn is a pawn. It's up to black to prove his activity is worth the pawn. I think the position is closer to equal.

what pawn are we talking about here? I am questioning my sanity cuz I just can't see where black loses a pawn

You are completely correct, I'm the one that needs to be questioning my sanity. I was playing through some variations in my head (miscalculating, of course) and inadvertantly posted about it. Sorry about that

This move without comment scared me that i missed something tactical. But i don't see it.
After 20. b3 and mass exchanges (cxb3 21. Nxb3 Nxb3 22. Bxb3 i might end up on the very slightly worse end of a very drawish position because of his pressure against f7. But it should be manageable.
If he tries instead to bring his knight to d5 via f1-e3 he has to deal with the pressure on b2 first. This should give me enough time to prevent his maneuvre, probably Sveshnikov-style with Bg5 or given enough time more actively by Be7-c5. Let's see what he has on his mind.

looking again, on b3 i can probably answer c3.

I think White's Bxf6 was the wrong idea. After Qc3 instead of Bf6, White has a normal position.
Imo, after 20.Qc3 Rfb8 21.b3 Nc6 and Nd4 only Black can be better.

Yes, I agree with John_Douglas. White should be much worse here because of that bad bishop on c2; Black's counterpart seems better placed on e7, so even on 20. Qc3 Be7 as it's not clear that the Rf8 should be placed on b8.

At first I thought I missed 20...Qb6 but I think I'll play something strange to respond to it 21.Ra3 to prepare b3. I feel like the b2 pawn is safe because if Rxb2 I have Nxc4 and I should be fine

but what about Qb7? white can't respond Ra3 because of Rxb2 Nxc4 Nxc4 Qxc4 Rc8 winning the bishop, so white would need to play Ra2 or something?