I'd reiterate what others said. I'm not on the spectrum but several people have suspected so as I'm naturally very introverted and pretty weird.

Eventually I developed really good social skills, at least in certain contexts. It can be done. One breakthrough moment for me was realizing you can just ask people questions and they are happy to talk about themselves. Jobs are a great subject. All kinds of people play poker: cops, fisherman, rich guys, athletes, salesmen, entrepreneurs... learn to take a genuine interest.

Spergy people can be off putting when they are totally self centered. Develop compassion and an interest in others, which also helps at poker.

One good piece of advice I heard on bullying/criticism is to stop being a b.

If you're very sensitive to criticism it's probably because you have a fear that is true, or you have low self esteem in general and think others are exposing the truth you don't want to face.

Like, if someone said you were a spy for Joseph Stalin or a lizard person you probably wouldn't be offended and just think they were crazy. So why do more plausible insults bother you?

Just embrace the fact that you're flawed. It's fine. If you're short, you're short. If you're fat, you're fat.

Either the flaw you have is real, and that's just a fact. Maybe it's something you can work on. Maybe it's just a fact of reality. Oh well. Why worry about some basic fact like being old, fat, big nosed, etc. Would it be less true if nobody said it?

Or the insult is false, so who really cares. It's like someone saying you are a Soviet spy.

If someone tries to use words to create a negative reaction in you you can defeat them by not having that reaction.

If someone says you're going to blow the dealer later say "only if he makes at least $10 in tips."

Sure, but those guys went there specifically for that experience. I thought about trying that game out myself.

A casino is almost the last place on earth a person should need to be concerned with literal "bullies." There are cameras everywhere, and armed security available quickly if anything goes wrong. Even if the person is scrawny and nervous as OP describes himself. In the worst case scenario, if he wins a bunch and is still afraid then he can get security to escort him to his car.

But what OP describes as "bullying" is not physical attacks or threats. It's mostly verbal. The fact, which everyone here seems to be evading, is that the world is full of awful trashy people with few or no redeeming qualities. Some of these people have money and an urge to gamble. They tend to concentrate in places where they can satisfy that urge. They are not worthy of your respect. The only attention you need give them is that required to find out how best to take their money. Be courteous to civil people, of course, but that shouldn't need to be said.

A hog farmer profits from handling swine, but he has to learn to ignore the stench. Anyone working in a casino, which includes winning poker players, profits from handling two-legged swine. These usually don't stink, but do make a lot of hideous noises. If you learn to think of their speech as nothing but that, the grunts and squeals of animals, you'll find it much easier to ignore. It's simply a necessary condition of working with filthy beasts. Visualize them as delicious sizzling bacon. If one is trying hard to provoke a reaction from you, it might also be useful to visualize each step of the process you'd use to turn him into bacon.

If this is beyond your ability, you'll just have to find some other way of making money.