Hi, watino, welcome to PsychCentral (PC).

I don't know that it is all about you; she may not be able to cope well, personally, with being afraid and being threatened. I don't think it can be mended because it cannot be undone, there is no chance of "only joking" or whatever? Reasons or excuses can't give a clean slate (where it can be assumed one does not punch things/threaten). T needs to be able to trust you as much as you want to trust her.

You say you would not punch her/anybody but you do punch, which is too far for some people. I use to talk about how I wanted to smash my fist down my stepmother's throat but, for all my angry words, they are just words (which T's like :-) I never acted out. If you did not control yourself punching the table, there's no way to know if you will/will not control yourself later/if things get worse. Psychotherapy is only words and when we cross that line (or are not able to use words/don't talk, etc.) then it is not a treatment that can help us at that time.