Rant-I don’t know what to do..

Sorry this is super long..

So I’m 27 weeks pregnant, and my S/O and I are renting a 3 bedroom apartment with my father because my father was in a tough situation where he needed to move out of where he was living and we were already in the process of looking for a bigger apartment to have space for the baby so we decided we would get a place together. We split the rent 50/50, my boyfriend and I together pay $750, and my dad pays $750. We split hydro and renters insurance, and my s/o and I pay the entire internet bill. I’m currently on welfare, in the process of getting disability due to a genetic condition, and my boyfriend works full time. My dad has recently gotten his hours cut because of this pandemic, and now wants to split the rent 3 ways instead of in half like we’ve been doing. Which would be fair except we have the same amount of space, my bf and I share a room and my dad has a room, currently the spare room which originally I wanted to be a nursery, is full of boxes of my dads tools. And instead of letting me turn it into a nursery, he wants to have it as a “chill room/gameroom” and fights with me every time I try to say no, so I gave up on that and we have to have the crib and all the baby stuff in our bedroom (which I was planning on having her in a bassinet in our room for the first while anyway) but our room is TINY. We have a double bed, one dresser, and a tv stand. We have to get rid of the tv and stand to be able to make room for the crib, and will have to keep the babies clothes in bins under our bed because there’s no room for another dresser, and the rest of her stuff will be crammed into our tiny closet. So I don’t really think it’s fair for us to be paying double the amount of rent that he is, when we will hardly have any space for ourself when the whole reason we moved from where we were living before was for the purpose of having more space, meanwhile my dad just needed away from his gf that he was living with so we offered to help him. Not to mention we buy ALL the groceries, we spend more than 900$ a month on groceries and I cook supper for my dad every night, I think he’s done groceries maybe twice since we’ve moved here and it was mostly things for himself like cookies and ice cream. He also NEVER cleans up, I wash all his dishes and do all the housework and never complain about it because the way I see it is I have to get used to doing that anyway being a mother. Well my dad and I got into a huge fight the other day about rent where he started screaming at me saying we were taking advantage of him and it’s not fair that he has to pay so much, swearing at me, telling me I’m selfish etc, just because he’s stressed out about his hours (he’s still working 6hours 5 days a week but he used to work 10 hour shifts) and I just really don’t think that’s the case. But when I tried to express to him how my s/o and I see it he just flipped out and threatened to bail on our lease and stop paying rent completely which would majorly f*** us over because we can’t afford to pay the entire rent+bills by ourselves, on top of trying to buy everything to get ready for the baby which we’ve already been struggling to do which I’ve been SUPER stressed about. I just don’t know what to do anymore, things are so tense now when my dad is home and I hardly ever want to leave my room now because every time I see him he just tries to guilt trip me. He also won’t sit and have a conversation with my s/o about finances even though I keep telling him to because it’s their names on the lease, cause he knows he can’t push him around the way he’s been trying to do with me. I know this is a super stressful time for everyone, and I want to be able to help my dad more I really do, but I need to be able to focus on getting things ready for the baby and I shouldn’t have to be so damn stressed out and upset constantly and I just really don’t know what to do at this point 😩 Am I being unfair?