Oh boy. Much sympathy and many hugs to you. Abusive childhoods can really mess you up.
One thing I've learned, however, is: Deciding not to do something isn't enough. Deciding not to be angry and abusive like your parents is basically useless unless you develop the tools to do something differently. You'll still feel hurt, you'll still feel angry, and unless you replace the coping mechanisms your parents taught you with something more constructive, you'll just keep reproducing it.
Which is not your fault. It just means we can't produce perfect solutions and emotional responses out of thin air. You have work to do to get over this.
I half suspect that you weren't so much depressed as repressing everything that's now flooding out, but I'm no therapist, and we here can't diagnose. Either way, have you seen someone professional for the depression? Can you keep seeing that person? If not, are you at school and does the school have any counselors on standby? Does your budget allow you to go find proper help if free help isn't available?
Do you have a Team You? Friends and family members who you trust and with whom you could talk this through? Because your uncontrollably petty anger doesn't come from nowhere. It's likely a lifetime's worth of anger bubbling at the surface, and you need to deal with the actual anger, the one you feel towards your parents, your ex, probably yourself as well.
(and for the record, I know there's a lot of cultural pushback against it, but it's absolutely okay to be angry at ****ty parents)
I really, really, really recommend you find a professional. They can help you with cooldown methods, anger management, etc. Sometimes, just making that first bit of headway can be a tremendous help.
Because anger can be a force for good. Anger is what helps you stand up for yourself and others, and sometimes is the only way you'll get **** done. But you need to control it. Not repress it, not let it loose. Anger needs to be the fuel for constructive behaviours (such as standing up to abuse), but you need to learn those behaviours before anger can be helpful.
You can do it. It's hard work, and it's frustrating, but you deserve better than what your parents gave you. Go get it.