Worried😫

So, I need to know if I should be worried. I’m 28 weeks with twins and I’ve only gained like 6-7 pounds the whole time. The first few months my weight didn’t move at all and I read that the placenta is supposed to weight like 10 pounds and then all this other stuff. Does that mean something isn’t working like it should? I mean this one woman said she gained 35 pounds with one baby. My girls are a little small and I’m just wondering if I should be gaining more or if it’s something I’m doing to cause them to be tiny. I love my babies but I hate what this pregnancy has done to my head. I think my husband is always doing some shady shit when he’s not doing anything. I’m always thinking something is up. And I think it’s because I’m trying to control some part of this because I can’t control the fact that I couldn’t help my dad unload furniture or carry my neighbors kid home cause she fell asleep. I had to wake her up and all this stuff I used to be able to do. I feel like a terrible mom thinking that way. I just can’t help it.