I've had lower back pain for 9 months now, I felt a moveable lump in my left lower back which is quite small and wasn't visible in aultrasound ,
I've done blood test, aultrasound, X-Ray and CT- scan. All was normal
My physiotherapist told me there was nothing wrong in my body structure
I cannot sit for more than 20-30 min without pain though
Pain goes down the leg , I feel nome ness and heaviness in my left leg when sited or laid down
If I sleep on my stomach I feel better, I cannot sleep on my side without putting a pillow between my legs
I got depression because of the constant pain ( during the weekend it gets a bit better because I don't sit like when I'm at work)
I had an injection 2 days a go
i still don't feel comfortable and I'm so scared if it doesn't go away
My Dr told me to get another injection if pain remains after 2 weeks
Please help me what should I expect and what should I do?
I'll turn 30 in 2 months
I am 165cm and 56 kg
I have Pcos but I am told it's not very bad

Do you have any idea what could be the problem?
Should I see a specialist?
Do I need to do MEI?
How can I get rid of it?

Thank you