3rd unplanned pregnancy, abortion or no abortion?

So about 7 months ago my husband and I had a miscarriage and we weren't expecting to have another baby for a very long time. on Mardi gras we were a little irresponsible and I am now about 7 weeks pregnant, we are not financially able to support another child and the stress of another baby concerns both of us. I know that it is for the best to get an abortion, and I hate saying that because I've always been very much against it, but I don't want to.

We've talked about it over and over and over and unless somehow he wins the lottery or we come into a lump sum of cash, we can't afford to keep the baby and there's no way that we could carry the baby to term and then give it up for adoption when we already have two children, five and six, I just wouldn't be able to let go. my mother-in-law has helped us financially over the past eight years and she's a wonderful woman and I love her very much. she has worked in healthcare and solidify and she believes that if the baby is aborted before 22 weeks that it's just a fetus and it's not a living breathing child because it cannot survive outside of the womb.

Even though I worked in healthcare from the time I got out of high school until after my husband and I had Matt and first started dating I wholeheartedly do not agree. Our relationship, my spouse and I, has been Rocky and she is worried that a third child will destroy us and I understand her concerns. but I don't want to have an abortion and I am just losing my mind because I know that I have to in order for my family to survive but at the same time it's really hard for me to just continuously talk about it with her when she doesn't have the same views that I do. I know she means well and I appreciate her help and advice but I do not want to keep talking about it or there's no way I'm going to be able to go through with the abortion.