How to explain unfinished master degree on my resume and during an interview? My master degree was biology in research mode, it was 4 years after undergraduate degree.

I didn't finish it because of a lot of dramas throughout the period of my study and I can't take it anymore. My supervisor resigned and got a professor job in the US, and because of their office politics and I ended up with a nominal supervisor from unrelated field. Co-supervisor is exploitative and only care about adding shit ton of workload to earn him more grant money after my first supervisor left. He didn't care about my research. My dean was the same dishonest and exploitative type, I had the same unpleasant experience so I didn't ask for his help.

My first supervisor in the US is the last straw that I decided to quit. He has terrible temper tantrum, lots of insult and personal attack. My lab mate had depression from this and I got PTSD. Why I didn't leave earlier? because he made fake false promise and manipulate us that there's something we could still hold on even after he left. Then covid hits, no more grant money and I had breakdown. Can't even do video call with first supervisor due to my PTSD.

I decided to work in another field but I don't know how am I going to explain the gap with unfinished degree. Should I be honest and say I don't agree with my supervisor's behavior but I won't comment on it, or should I not mention anything about the experience and just say I found my new interest in this particular field? Will the first answer make me seem irresponsible and a negative person?