Try this
Pumped,
I know exactly what you are going through I seem to have a difficult back. This is a little different than your problem but I think it may help you out.
I went to my ART therapist finaly about my back pain when doing Deads squats and bent rows, it gets so bad I can barely breath. Well he said A LOT of bodybuilders have super super tight glutes and over time scar tissue developes.
WEll anyways to the point Try really stretching out your glutes and hamstrings. This has helped me greatly and it may alleviate some of your pain.