I'm so TIRED of being pregnant already ...?

I'm due in less than 4 weeks and I'm so tired of being pregnant. I feel huge and heavy and have constant back pain. I can't sleep or find any comfortable position to try. I don't know what to do, I'm GOING NUTS!! I feel like I'm starting to be snappy with everyone. Like with my husband I'll tell him how I feel and he says "I'm sorry babe" and I'm like "No you don't understand blah blah blah" I feel bad but I can't help it, it seems cause I'm so frustrated. I'm so sleep deprived and oh god I don't know how to change the way I feel. HELP!?