Sorry LOL, that sounds awful. Babycentre says these are the symptoms of SPD:
Back pain, pain at the back of your pelvis or hip pain.
Pain, along with a grinding or clicking sensation in your pubic area.
Pain down the inside of your thighs or between your legs.
Pain that's made worse by parting your legs, walking, going up or down stairs or moving around in bed.
Pain that's worse at night and stops you from sleeping well. Getting up to go to the toilet in the middle of the night can be especially painful.
(https://www.babycentre.co.uk/a546492/pelvic-pain-spd#ixzz3wLwoEMBg)
They say that going to the physio and strengthening the support muscles around the pelvis can help. I suffer from neck issues that trigger back pain, especially in my lower back and hips. I've found visiting the chiropractor monthly really helpful (I'm going today!) to loosen locked joints and free up muscles. Maybe that could help?