Back help!

Hi everyone! I’m a 21 year old female, and I was just wondering if someone can help me out with this. I used to go to the gym all the time in high school, was super super athletic and involved in sports like lacrosse and track. When I was 18 I started getting this back pain when playing sports. Then when I was 19 I had to stop lifting and running because I was constantly irritating my lower back.

I’ve since been going to hotworx, cycling and walking as the saunas been better for me but decided I wanted to get back into weights again. I’m currently 21 now, I started off easy with 5 pound weights and 8 pound weights for upper body. The next day when I woke up I felt pain in my lower back. I’m unsure what to do or how to resolve this problem as it’s been going on for years every time I do a workout (especially with weights). I take my time stretching so i’m super confused, I made sure not to arch my back and such. **Please note too i’ve been to doctors for endometriosis as well but it’s been super hard to get confirmation as they can’t tell for sure unless I get surgery** Not sure if this is an endometriosis issue, a form issue, or something else i’m missing. Please if someone can give me any advice as it’s been really holding me back from reaching my fitness goals and making it hard to be consistent!