Mother-in-law moving in, AGAIN!

My husband and I have been together for 9 years, and in that time my mother-in-law has moved in with us probably 6-8 times for various periods of time ranging from a month to almost a year. She makes very little income and has always relied on men for a place to live, so anytime she breaks up with a boyfriend she is left homeless and without any money/savings. We are always there for her because that’s what family is for. But to give you some background, we have offered countless times to help her put a down-payment on a house or to pay her first and last month’s rent to get her own apartment… But she never ends up taking us up on the offer because she always ends up getting back together with a boyfriend or finding a new guy and moving in with them instead.

Well yesterday she calls us and says she’s leaving her most recent boyfriend and she needs to come stay with us. I’m at my Witt’s end here… My husband and I have a two year old son and I’m 6 months pregnant with our second child. Our house is undergoing extensive renovations right now and the only place my MIL can sleep is on our basement couch (and the basement is FULL of storage and furniture because of the renos). I work 40 hours a week at a high-pressure job and between the stress of work, home renovations, toddler drama and pregnancy hormones I’m about to lose my mind.

How do you tell someone (my mother-in-law) that enough is enough and you just can’t do it anymore, without ruining your relationship? I can’t have her staying at my house again. I don’t need her help, I need my space. I called my husband today in a melt-down and told him that I couldn’t do it anymore and he is very understanding. He’s going to do the best he can to find her an apartment ASAP. I feel awful that my husband is being put in this situation by both his mother and his wife. The responsibility of finding his mother a place to live always falls on him and it’s not fair. I’m angry that she doesn’t see that, or that she doesn’t care enough to do something about it. I’m also angry at myself to not being more understanding of her… am I a bad person for feeling so much resentment towards her? I’m just so sick of being put in this situation.

I don’t know what to do 😭