SO and money.... (Long)

I make good money, but not enough by myself. $29/hr, but after taxes and health insurance and 401k that leaves me at about $1400 every two weeks. SO makes about $300 every week, so like $600 every two weeks. Before him I was on my own and lived within my means and also made more because before I was pregnant I could work overtime. Now I can't. My work will pay me for 7 weeks of being off work. My doctor will give me 6 weeks off work for a vaginal delivery and 8 weeks for a c section. I'm trying to last as long as I can at work so that there will be little to no time that I go without pay. As a safety net, I've been working on a savings account. Before we got pregnant I was the only one contributing and it was about 600. Since the baby, I've put ANY spare money in there, just to make sure We're not out on the street with a newborn. He helps with bills, usually gives me about 500/mo. Is it half? No, but I'm fine with that because some of the bills were established before he came into the picture and he wasn't there in the decision making process.. Also some bills are just flat out mine, like my loan debts that he just shouldn't pay for. I'm happy with the 500/mo that he pays because it frees me up to put more into the savings. Savings was at 1600. His car started having trouble. I was fine going into the saving bc I'm due in November and I don't want my child in a dangerous car when she's with him which will be a lot. So the car situation brought the savings down to 1000. I was obviously uncomfortable with that because we determined that we need to save 2800 before the baby so that whatever happens we can be set for a month with him still working and me not. So it's been a week since that and he paid me back 200. Not sure if it's for bills or for the savings but it's all he can do right now so I take it. Keep in mind: since the car trouble in holding down the bills by myself. Which is terrible because I'm having to go into the savings just to stay afloat on stuff. Now we don't live like king and queens it's just that his family is always falling on hard times. In May we loaned his mother $300 out of the savings and never got it back. I didn't complain because I know she doesn't have it and I think somehow in his mind he thinks by paying me every month, somewhere along the line he paid it back. False because what he pays me is supposed to go to bills. So that's exactly what I use it for. So I took that Loss silently. Now he found out on Saturday that his mother is basically being evicted on Monday (today). Last minute! But I understand because it's embarrassing, you don't wanna have to share that info with somebody. Well he has to put an apartment for her in his name. We are talking about marriage, so while just a boyfriend right now, bad credit will at some point affect me if we in fact do stay together and get married. He claims his credit is already bad. But he got approved for the apartment in his name so I'm thinking it must not be too bad. Well common sense will tell you, if his mom can't take care of her own credit, how can she take care of his?? By no means would she deliberately, but she just can't stay afloat so it's inevitable because the place she's moving into has the same price for rent 😣. I love his family to death. We are really close for how long we've known each other. So anyway today he gets the approval for the apt and his sister was supposed to pay the downpayment to help out. I hear her say "don't you have some type of account that you can go into, you just have to put the money back?" 😡😡😡😧😧😧😕😕😕😩😩😩😩😩😩. I just about died because he told them that that money was available and the fact of the matter is it just took a huge blow because of his car. And now it's gonna take another blow because of this and we have less and less time before the baby gets here. It's no time to get it back up 😔😔 I been stressed about money since I knew I was having a child which is why I started saving, not for somebody to come and take what they think they rightfully own because they contribute to the bills. I hate atguing about money!!!!! But I have to be set for my baby. So in my heart I know he's gonna ask to take money out of the savings. I'm gonna say how I feel. Then I will give him half of what's currently in it (500) tell him that's the MAX that he possibly owns of it and let him know that I can't help support another family while my own is falling 😔 I feel so bad because I love them but and I know he wants to be able to provide for everybody but it's not something that's possible. I'd rather my bills go back to normal and I struggle to support my child by myself with his help from a far whenever he can than to let somebody else constantly take. Like I said I hate arguing about money but I feel that this is the last straw 😔