you've got SPD, I experienced the same pain & I'm sorry to say but it did continue to get worse until the end of pregnancy. Can you get to a physio? There is also a belt you can buy or even hire from the hospital that will hold all your ligaments together. (belly belt I think its called, mine was only $30 to buy)
Try not to walk long distances & try to keep your legs together when getting out of car etc (swing your body instead of one leg out at a time)
A pillow between your legs at night will probably help too & for my last 4-8 weeks (cant remember exactly) I slept on the lounge sitting upright with pillows all around me supporting me, I couldnt lay down at all by that point.
Alot of people say theirs went away straight after birth, I hope it does for you too (mine took 7 weeks after birth)

I really feel sorry for you, its incredibly painful & its the one thing that puts me off having more babies in the future as apparently it gets worse with each subsequent pregnancy.

I hope you can ease the pain xoxo