Almost unbearable back pain in evenings

Celeste • Pregnant with baby #1 EDD April 3rd, 2016!
By the end of the day my back is so sore all over, severe achiness. I'm in pain even when I lay in bed. I'm constantly waking up in the middle of the night too and I am only 24 weeks. I have used a heating pad for short periods (I do have some relief with the heating pad). I sleep with a full body pillow. Any other suggestions to get some relief?