Issues with finishing?

I’ve recently gotten myself into a relationship and during sex I’ve had issues finishing. Part of it is I feel distracted, (maybe adhd playing a part?), feeling exhausted (I’m not particularly healthy and lowkey takes a toll on me). It’s weird because I can jerk off to no problem, not even using porn, but when I did jerk off next to them it was far harder and was not easy to cum at all. I’ve always only really jerked off without lube, while lying down, which I think is unfortunately the problem. There was one time I came while standing up, but I was fighting for my life with that one. Looking mainly for tips with me, my partner is very communicative and understanding and tbh they don’t mind me lasting longer.