You sound like me! And I work at a uni so I know what you mean about having to walk all over the place. I have been getting progressively worse too. I spoke to my Ob about it and he said the best people to get treatment from for this sort of thing are physios and osteos which is what I was already doing. And also the use of a support belt.

These are the things I have been doing which have been an enormous help:

*Pregnancy support belt - just got it, but well worth the investment
*Regular Osteo visits to an osteo that specialises in obstetric osteopathy
*Twice weekly Pilates sessions with Physios
*Back and belly body pillow - another great investment
*Limit bending tasks and moved kitchen around so things used most often are in easy reach
*taken advice from the pelvic instability website

Please feel free to PM me for more specific details if you want them!

Good luck - I know exactly how you are feeling!