A heating pad as well will help when you’re resting. Maybe you need a pregnancy support belt as well. They support your lower back and stomach. I just got one yesterday for ligament pain in my lower stomach and it does wonders!
I have been having awful back pain as well and round ligament pain. I have found putting my legs up helps with the back pain a little. Also I have been putting on Tiger balm to help relieve the pain. I literally hurt everyday for the past week and a half. I was in an ultrasound yesterday and wanted to cry laying on the table for 45 minutes in pain.