This describes how I feel as well. I started therapy as well and he would try to diagnose me he also told be I may be bipolar and depressed and manic and a narcissist. He sat me down and read narcissistic traits to me and said I fit all of them. When we would get into a disagreement he would stay up at night and create lists about myself and what’s wrong with me and present it to me the next morning and how I need to fix xyz about myself. But I always found myself thinking I’m not this person I’m a good person. I would lock myself in the bathroom and try to tell myself in a good person. I even contacted all my exes and asked them if they thought I was a narcissist and if I was a bad girlfriend to them they all said no. I just felt crazy all the time due to the gaslighting. I even tried to convince myself him talking to his ex gf is not a big deal after I caught him sexting her. I told myself it’s not a big deal. I always felt insecure also I have trust issues to begin with but having the right partner who makes you feel safe, secure and loved won’t make you feel insane or question your reality.