Have significant lower back pain/stiffness, especially when waking up. exercise and stretch daily, but sit most of the day. should i see a physiatrist?

Back pain: Morning stiffness is common with arthritis. A physiatrist will be able to help diagnose and treat the cause.

Back pain: The back pain can be caused by muscle strain, spinal stenosis, ruptured disc, nerve impingement ... It sounds like you experience some arthritic pain if your pain persists, you should seek help from a health care provider (pain management doctor, physiatrist, neurologist ...) you might benefit from a comprehensive evaluation and treatment.