Severe back and oblique pain

For several months I have had severe back pain in the lower lumbar area and my left oblique ( not sure if I spelled that correctly) hurts as well especally after I eat. The back pain comes on after I start to walk or do any kind of physical activity. The pain is so unbearable that I can not even stand up when it happens. Sitting down and taking pressure off of my back usually eases the pain after 10 to 15 min.

The oblique pain is unusual, If I consume a liquid, I usually feel pressure or soreness on my left side  just above my hip soon after the liquid is consumed. From looking at pictures..does not seem like kidney area but since I am oerweight it maybe kidney area.

To decribe myself, I am 310 lbs and 5"11" so I am overweight. I have a 44 inch waist and I just recently started to work out again but of course I am limited as to what I can do due to the pain that comes on right after I start to move around.

I though it could be due to the large belly area drawing down on my lumbar section but then I started to get the "cell phone ringing " sensation in my right hip.

I am checking here first before going to the doctor and getting set up for a ton of unnecessary tests and work ups.

anybody got some ideas?