My lung has been hurting for months

Why?? I went to the doctor a few months ago an they couldn’t find anything wrong, they X-rayed me n said my lung isn’t collapsed and that they don’t see anything wrong, Gave me some ibuprofen and the pain never went away it’s been about three months, I smoke weed and nicotine, the pain doesn’t feel worse when I smoke or take a deep breath, it just constantly hurts and it’s only on the left side, and I also feel it in my shoulder blade, it goes away for a few days maybe a week, and then it’s back. It’s not like a shooting sharp pain, it’s more like an ache, and I just wanna feel normal again. Is anyone going through this also? And does anyone have advice??

edit: thank you sooo much for the advice everyone I was really having trouble quiting smoking but thanks to you guys I genuinely feel cringy when I go to grab my vape, and I was having panic attacks because I can’t go to the doctor, but knowing all the non life threatening things it could be and probably is makes me feel much better, thank you everyone for caring enough to leave advice and motivation ❤️

Another edit, the pain has moved to my side, it feels like it’s on a rib? I felt fine when I woke up and then as the day goes by it slowly gets worse, I’m almost sure it’s not my lungs, I did forget to mention that I am about 30-25 pounds underweight. So a lot of you are probably right about it being nerve impingement.