Lower Backpain. Suggestions and help.

Hi, I have arthritis since 12years. I used to get back pain, arms and legs pains periodically. But from past few years no leg pains after I have started some physical activities like walking, running and some exercises to reduce my tummy. But from last 6 months my lower back is paining intolerable. Currently I am taking physiotherapy but I don't see any improvement after I had 10 sessions. So, plz suggest me how to get rid off this back pain which makes me nothing less than handicapped as I am not able to do my personal things as well. First of all, I would like to know this is because of arthritis or something else. If because of arthritis what the best treatment I can go for as my physiotherapy was not successful after I had 10 sessions. I really appreciate any kind of comments, suggestions and help. Thanks in advance🙏