Left psoas pain I interpret as anterior hip pain. This could be your hip joint as well as a nerve referral pain. Obviously, lower back pain is located in a different spot and is normally generated by the lumbar spine. Hyperlordosis doesn’t occur overnight so your earlier X-rays would be helpful to determine your current lordosis which I suspect is within normal limits.
It sounds like flexion (bending forward) relieves your pain. Backpacking causes spine flexion to compensate for a heavy load posterior to your spine. Mountain biking and skiing are also flexion activities. You might have a facet disorder> See:
https://neckandback.com/conditions/lumbar-degenerative-facet-disease/
Dr. Corenman