AIO For wondering if the Boyfriend has a chemical imbalance?

I (19 F) and my boyfriend (21 M) have been together for 2 years hes had anger issues but never this bad. In the beginning he hid it well and now he admits he needs and and just filled out his health insurance to see a psychiatrist, him and I both believe its possible to be a chemical imbalance in his brain. But Im lost. I feel like his anger is only let out on me, yes he can get angry and things or people but im always the target of the anger and it gets tiring. When im with my family or out in public with people, he doesnt randomly have a fit of rage? But yet when we go back to our apartment its like nothing stops him. He can be very kind he doesnt have much money because he hasnt got his ged yet so rent is basically on me, wifi, and sometimes electricity if he can cover it. Which he says he wants his education I think he just lacks to confidence to know that he can! But he said he would after he got his bike fixed and start getting registration at the office it just got fixed today so I hope he keeps to it and I believe he can! Like I said he doesnt have much money but if so he spends most of it on me to get me food when we have nothing so I know he loves me you know? But his anger causes me to resent him, Im always the one cleaning taking care of the animals even though most of the animals were his to begin with. When I try to bring these things up sometimes itll be totally normal he will take accountability and try for like a few days then it fades, or he gets angry saying how tired he is from work which i could understand but he doesnt get much hours and meanwhile I work from home yes there is so luxuries with that but not much when your maintaing and constantly cleaning, having to take care of all the critters and working with barely any sleep so we can have a house over our head. I never expected this first getting our apartment I thought it would be 50/50 and we will both be able to save now I can't save anything. And with all of the the anger issues are getting worse to the point I feel like I cant feel safe. He had gotten mad at me over a game or bringing up cleaning I cant recall really what set it off but I walked to the other room saying Im done with you and this conversation this is just straight up disrespectful. And its like a flipped switched he kept defending himself on why he is angry yelling and cussing at me so I closed the door with only myself in the bedroom. He pounds on the door while slamming into it trying to get it open yelling at me to open the door can we talk while it getting worse to I was sobbing sitting on the other side of the door so he wouldn't come him then he started cussing me out then said "you know what I should put this cigarette out on you" then caught himself and apologized profusely and walked away. I dont know if its a chemical imbalance anymore and Im tired. And everytime i say we should take a break from one another because it seems like me being here I just makes you more angry than he claims that I don't make him more angry and I help him but it doesn't look like that at all. And then if I stick my ground on it then he threatens to commit suicide because he says "hes nothing without me" and I remind him even without me he has a life and a future but it scares me. My dad committed suicide Ive felt guilty since I was 12 thinking maybe I could've done something. I dont wanna feel that same guilt with him. And it just hurts I feel so stressed to the point of disappearing. I just want to be loved. I just want him to be nice to me. I hope the psychiatrist helps him I know he needs it but Im also wondering is this just who he is? Im sorry for venting but any recommendations or advice would be appreciated.