Frustrated

I'm pregnant with baby #3 but I'm having some depression and feeling a bit overwhelmed because my husband does not help much at all with the kids. I was working up until 2 weeks ago and I'm still looking for another job at 23 weeks. I'm really raising my kids alone and sometimes I feel like I want to leave him because there's no point of being in a relationship with someone who doesn't put in 100%. He says with this baby it'll all be different but yeah right.. Why don't change things NOW and not after he's born?! I just feel so alone. Anyone else feel the same?