I had SPD with dd, so i know the pain!!

Do you have a support belt or band?
I know there is exercises where you lay on your back and bring your leg up (one at a time) until you feel it resisting going up anymore and you count and release and then do it again, it just release's the muscles for a while to get some relaxation i guess,
Also lay on you side and breathe in for 40 i think like use the muscles in your abdomin and then release and keep doing it for a while, i have no idea what this is for but thats one of the ones physio used to do... lol
Also when getting out the car, turn your whole body to put both feet out the door flat on the floor to get out, dont take your steps huge..
My mind is tired but i cant remember alot right now but ill be back!!
But get a support band and/or belt, they helped me heaps, uncomfortable but awesome stuff!!