Hey OP - Some good advice in this thread, hope you take it to heart.
I agree with most that you should drop whatever guilt you have over the divorce. That decision is made and don't think so highly of yourself to believe that your ex can't survive without you.
Also, obviously your new gf is not who you think she is, but oh well. Is anyone who we think they are? That doesn't really matter either.
Bigger concern is that it seems you have a warped idea of what love is. Don't confuse feelings with love. Just because sparks fly and you really connect with a person, doesn't mean that's love (and the absence of those emotions doesn't mean you're not "in love"). Love is action, love is a choice. And loving someone doesn't mean you have to sacrifice yourself completely; you just need to communicate your needs to each other appropriately and take turns sacrificing. Understand that and your next relationship will be much better. You clearly need to learn to communicate better, which I think you've admitted, just hope you take actionable steps to improve that.
And if you get nothing else from this post, please remember this: DO NOT SEE YOUR EX EVERY WEEK! Seriously man, wtf? That's just not smart on so many levels. Mail in your checks and wish her well. Trying to appease your guilt in this way is not helping her or you. You do not need to "be there" for her. I mean, clearly you see the problem here, right?
If you don't listen to any of this, then I'm looking forward to your post in 6 months when you tell us how being away from your ex made you realize how much you really appreciated her and after seeing her once a week for 6 months, you started having feelings for her again and you both "fell in love" again and now you'll live happily ever after since you've learned from your past mistakes. Not that that's a bad thing, it just means you didn't learn anything from your past mistakes.
Sorry, this turned into a bit of a rant. Good thread OP. Remember it's your life and no one else's, so stop trying to please everyone. Take care of yourself first so you can appropriately help others. Lastly, do yourself a huge huge favor and read this:
http://waitbutwhy.com/2014/06/taming...-run-life.html