Alright, this is kinda a two pronged answer.
One - How do you deal with an (allegedy) abusive mod team? Easy. Follow the instructions in this Meta Stack Exchange post.
(Basically, use the contact us link to reach out to the SE Community Managers. They're employees of SE. They'll look into things and take whatever action is merited, if any.)
Two - Dealing with what happened with your answer.
The first thing you have to remember - SE is collaborative. Anyone can edit any post (and either it's live or it gets marked as a suggested edit, depending on rep level and/or if you're a mod or not). So moderators and/or other users might edit your posts to make them clearer, or take out bits that don't fit with the SE model or the site's scope.
If I had to guess, the edits were to take out some of the...less savoury and more accusatory language in your original post. You made a lot of unfounded judgements, calling the girlfriend "sadistic, narcissistic and emotionally unstable", labelling her as emotionally abusive, etc. A bunch of that violates the Be Nice policy, which I know you're aware of because I know you referred to it in one of the many comments that you left.
Also...we're not here to diagnose people. We're not here to be lawyers and give free legal advice, for a variety of really good reasons. One of the bigger ones being that, well, you cannot and will not ever ever ever get the full picture of a situation from a few paragraphs of one single question on an SE site. We don't want to set precedence for this sort of thing - it can have real life harmful repercussions if we open ourselves up to this sort of thing. (Regardless of what you think you might know about how things are legally defined anywhere in the world).
Catija was trying to leave the bulk of your answer intact, the bits that were actually helpful to the OP while removing the parts that were quite rude and/or tried to dispense legal advice.
HDE removed your answer when you reposted it, because, well, you were pretty much gaming the system at that point - you didn't like it was locked, so you posted it again. This isn't how it's supposed to work - if a post is locked, it's for a reason. It gives people time to deal with whatever controversy is going on like calm, rational adults, without the distraction of possible edit wars and other such things. Reposting your answer circumvented that whole system, because you didn't seem interested in any sort of constructive dialogue.
That's it, that's all that happened.
Instead of reacting calmly and rationally, and following the Be Nice rule, and trying to have open dialogue about what happened, you kinda jumped off the other end of things and started attacking people personally. That's not going to win you any sort of favours. There wasn't any sort of censorship, it wasn't a personal attack - the mod team was just doing what they do best - moderation.