Trouble sleeping while pregnant?!

Abbigail • Married and expecting a little boy on May 16th, 2016!! 💙😍 we love him so much already!
It's 4:59. I've been up since 3:45 am ish. My fiancé is passed out next to me. I fell asleep at like 11, I was so tired I thought I was going to die. But I woke up and can't get back to sleep. This keeps happening to me! Falling asleep feeling like I haven't slept in two years and waking up a few hours later feeling like I've been sleeping for 2 years. Did anyone else have this problem? What did you do?