Reading your post, it sounds to me like bad stuff just kept happening (plus maybe you were triggered by something). So you ended up with all these emotional/chemical signals until it was just too much. Hitting the tank almost sounds more like it was a reflex or knee-jerk reaction than something you thought you would do?

Best you can do, as far as I can tell, is find a non-provocative person like a therapist to talk to. Take it easy. Do something to unwind and relieve stress and negative emotions. Also, try to forgive yourself for the fish tank incident so that it does NOT add to the chemical brew that, in all likelihood, started this problem.

I do NOT know you personally. My hope is that you can come out of this with the attitude that you are learning from your experiences at whatever pace, and build confidence as that works for you. Keep track of what it is that triggers you, and the feelings you get before an incident like this. You might call a time out if and when you feel that way again. Forgive yourself, and work on progress. Good luck!