Hello - I sympathise... I have it and it was really bad from 28-34 weeks but I went to see an osteopath at about 32 weeks who really helped. I'm now 35 + 3 as it's still painful but nowhere near as bad. The nhs physio I eventually saw was useless.
Do you have a support belt? Serola is the best apparently. It helps me quite a bit but you probably need to see a good physio/osteopath/chiropractor to make sure it's right for you - it could just keep your pelvis in the wrong position.
There have been a few threads on this recently so do a quick search for tips. And have a look at the 'Pelvic Partnership' website for a lot of useful up to date information.
But, for me, finding a good osteopath was key. Worth £47 a go , in my opinion... Good luck!!
I saw a craniosacral therapist once and the SPD disappeared. It was around 30 weeks, I think. Feel for you - it's awful. I would totally recommend trying craniosacral. It's a very light touch so you can't imagine it would do much but it did for me
Rest!! I was signed off work. Not siting at a computer and not walking/commuting has helped. Only move when you are not in pain. And try 'cat' yoga/Pilates exercises - when you are on your hands and knees and arch you back. And do your pelvic floor exercises too. But, mostly, rest! (It's very boring but you don't want to make it worse - or increase the likelihood of it lasting after the baby is born...)