This post might be all over the place. This is my first time doing anything like this but please bare with me. 
To premise things I am 21 and have a history of mental illness and have been formally diagnosed with PTSD and BPD. Besides what I’ve been diagnosed with, I’ve just been struggling with feeling sane at all lately.
My problems are almost always stress related. When things get tough, here are some things I experience.
I dissociate. I experience pseudo seizures. I enter psychotic states where I believe with my whole heart that I am not real and my existence does not make sense in this world. (This is a bit more complex but this is as far as I want to get into.)
A lot of my behavior, I thought was normal until I became an adult so I am still in the process of seeing mental health professionals for proper diagnosis.
The pseudo seizures, I used to only have when I would get in escalated conversations with my dad. It’s in the way he talks to me. I can’t argue with him or ever win. He never hears me and puts me down. When I bring up being belittled, I am sensitive or overreacting. I just actually can’t handle it. My chest hurts just talking about it. I have a completely involuntary physical response. My mom has said it seems like I am possessed. It’s a truly embarrassing thing I do that no one other than my family had seen... until recently.

I have a boyfriend I have been dating for 7 months now. He is 24. He has been incredible to me in so many ways. He helped me get my period back (gone for a year) after being malnourished (my own fault I was eating microwave lentil beans twice a day). He’s been wonderful about being accepting of my mental health issues etc. 

Lately, due to quarantine, loss of job, going back to school, and finding housing, my mental health has significantly deteriorated. His recent behavior has not helped either. I feel like he is finally tired of me. Everyday he is making little remarks about me and calls them jokes. If we argue lightly he’ll say things like “well this is gonna be a fun ride home” or “are you gonna hit yourself in the head again *eyeroll*”. 
He has been reminding me of my dad way too much. 
Our problems usually involve his social needs and my communication needs. He is late to everything and doesn’t care about wasting people’s time. He will make plans with people
And then blow them off for another set of plans he made himself. Every plan is last minute and I’m someone that needs some communication and time to mentally prepare myself for social outings. I never said I wouldn’t go or that I don’t want him to go. I would just like a heads up so I can go too... and actually enjoy myself. When he gives me no notice, I also can’t invite my friends and I end up being an NPC at every function.
It’s complicated.
He also doesn’t know when the party ends and will keep me out 2-3 nights a week past 5am even though I have school at 9am.
And so we fight.
And when we fight he is so intolerant of my needs that I get to the point where I have psuedo seizures.
It’s specifically when I can’t constructively tell him things that are taking a toll on me. I think about what I want to say and how I want to say it over and over again so it’s perfect. I never want him to feel like I am demanding things or giving him ultimatums. I’ll say things in the best way I can and it always somehow turns into psuedo seizures or mental breakdown.
Last night, I had one and I didn’t even realize I did it. He said I threw a fit but I could have sworn I was calm the whole time. I asked him, how did I throw a fit? 
He mimicked me.
He mimicked my psuedo seizure.
I was so shocked that I immediately had one.
I was so embarrassed I wanted to die. Hell I still am. I feel fucking sick about it.
I’d never felt so belittled and written off in my life. I knew it was something I did and I HAVE ALWAYS BEEN embarrassed but to have someone mimick me? To see for myself what I look like?
How can I ever feel good about myself again?
Does my boyfriend just think I’m a lunatic?
Why would he do that?
I don’t know what to do.

I explained to him that I am 21 years old and he can’t write off my emotions like I’m a child throwing a fit. I have always been very honest and open with him about my mental health and it’s dehumanizing when he does that. 
I have a hard time getting mad at him because I feel I am actually insane and deserve to be treated this way. Or more that nobody in this world will ever actually treat me any differently because I am ill.

I’ll respond to replies with any questions or advice. Please be nice. I actually can’t take anymore hits.