Pregnancy weight gain help.

So I’m 31 weeks pregnant and I’ve gained about 45 ish pounds so far. I’m absolutely terrified of what will happen after I give birth, with my body. I was working out consistently and eating great before I got pregnant. Then in my first trimester I was EXHAUSTED and so nauseas and the only thing that made me feel better was keeping my stomach full. Then in my second trimester I developed really bad sciatic nerve pain on top of working on my feet about 4 days a week so I didn’t really work out at all. And I was starving. Like seriously I feel like I don’t even know what I could’ve done and what to do now. Any advice will help. 😭