A.S.
I really hate to tell you this, but... pregnancy is pretty uncomfortable. It's normal to be uncomfortable, and I can tell you it will only get worse. Sorry... I don't mean to be a bummer. :(
Try to get up and walk around and stretch when possible. Over your lunch break, take a walk, during your 15 minute breaks, walk. Even if you can't go outside, just walk around the office, up and down the stairs, whatever. It will help you feel better and might help your little guy change positions.
While at your desk, you might see if you can get a footrest to prop your feet up too.
Congratulations and enjoy your pregnancy!