I'm starting to have doubt about this? i'm kind of scared?

I'm 43 and the dad is 46. We already have 4 children who are 24, 20 and 14 and 10 and now I'm pregnant and me and my hub have been wanting another baby ever since my sister had hers a 4 months ago and we thought about having one ourselves because I was there with my sister she is 38 and that was her 1st baby and it was beautiful. My hub has been having doubts and I told him it will be ok this will be a great child just like the rest but now when I think about it we are kind of old and i'm starting have doubts too and I just don't know I might not have the energy to raise this kid right. I can't really talk to my hub because lately all we have done was bicker and argue because he is trying to push me to abort my baby, I think that is extrememly selfish because in the end it is my body and my choice and I told him just leave me alone but I don't know what to do i don't think I could live with myself knowing a aborted my child, I know wouldn't be able to sleep at night without thinking how he/she would have been. my sister think I should have this baby and I do too but another part me just don't know about this, I'm just scared, I just wish I had someone to talk to because it seems no one knows what I am going through.