Greetings, sorry about the pain. You seem to suffer from flexibility issues at lower back and hips.
Next Steps
get to see a physio with knowledge about trigger point therapy and posture correction. in 3 sessions your problem will be solved 70% and once pain is down, physio will teach you exercises which will help loosen tight muscles and strengthen the core. it is best to hire a physio as your trainer for couple of months to learn and get trained for your back issues and also improve fitness as well
Health Tips
if any questions do let me know.