Third trimester blues

Sooooo... I'm almost 32 weeks pregnant and I've been having a really hard time dealing with everything. 
*disclaimer* I love my baby, I love my partner, I love that we are going to be a family. 
I'm really struggling with the reality that everything is going to be different now. My life will be completely devoted to another person and that is terrifying. I don't really feel as though I had my time to be selfish and to focus on myself, and now I have to give that all to a baby. I had so many things that I wanted to accomplish that now are going to be difficult, if not impossible, to complete. 
I try to talk to my partner about it, but all he ever says is 'I understand', which feels completely dismissive. 
Plus, I'm getting jealous and resentful of him. This was an unplanned pregnancy, so I feel very forced into altering my life. His life has primarily stayed the same since this happened. He can eat and drink whatever he wants, he can walk up a flight of stairs without getting winded, he can do basically anything he wants to and I'm this round sober blob with stretch marks who can't do a damn thing. Like tonight, he's going to go out with his friends and drink and have a good time and I can't. It pisses me off. I know it sounds incredibly mean and I shouldn't care, but I do, because after this baby I'm still not going to be able to be that carefree. 
I'm seriously just crying all the time lately :/ 
Please just tell me I'm not the only one who feels like this?!