need advice

So basically I'm 21 weeks pregnant and I've really stated to enjoy being pregnant, I love feeling baby move and kick and me and my partner had been trying for baby for about 2 years so very happy to be having this little prince, but lately I've started to feel I really don't want to be in this relationship anymore, my partner is very cold hearted and uncaring person and being pregnant has made it extremely difficult to put up with his cold hearted ways, I've always just excepted that's who he is but now my emotions all over the place I need him to be caring and kind to me but nope still the same, I'm probably overreacting but I'm So lonely and depressed and I Just need him to show he cares. I'm worried about how he will be when baby is born also. Me and partner never fight but lately his attitude has changed and he keeps snapping at me and I've basically had enough, if wasn't for baby boy I would just leave most probably but he's only started acting this bad since finding out I'm pregnant, I wish I could run away.