I agree with remar, it's best to just let it go. People can be very petty and even mean, but you have moved on and need to put this and those people behind you....they're not worth your time and energy. Getting "even" accomplishes nothing and it allows them to still have a "hold" on you emotionally and you don't need that. Like remar says...you've moved on, you're happy and that's what's important. Stay the better person and you will always come out on top! Take care.
I think the best thing to do is let it go. You sound like your in a much better state of mind with true friends now. It's sad that your previous co workers did'nt support you, but this can happen. Thinking about getting revenge will only set you back and you don't want that. You've moved on, your happy and that's what's important.
That's very unfortunate, I'm sorry you went through that, although I'm happy to hear that you are in a better place now.
You're best bet to look into your legal options would be to speak with an attorney. It definitely sounds as though you were in a hostile work environment that caused you a great deal of stress and eventually caused you to have to seek a new position. The fact that your immediate supervisor was involved rather than trying to help you is also deplorable...and wrong.
However, the burden of proof in a legal situation is on you. If the new job caused you to take a pay cut, then you certainly could seek damages for the loss of income, not to mention rank. Again, though, I think an attorney would tell you that you're going to have to be able to prove what happened, which may be difficult as it sounds like most of it was verbal harassment.
Definitely seek a consultation with an attorney and see what your options are. Best of luck!