Procrastination is taking away all my hobbies

I don't know if I may actually have ADHD or not because I have never been diagnosed (thank you parents that undervalue mental health) I don't want to self-diagnose but I have so many signs connected to ADHD it's insane. The most noticable sign is that I never can sit still, the constant procrastination and the fact that I can never start doing something, except for school projects because they're on a deadline I guess but they're still pretty hard to start. Starting something is so insanely hard for me that it's actually frustrating. I'm very self-aware about all of this but I still do it anyway. I have so many dreams and ideas I want to create and fulfill, yet I never start or I always say the usual "I'll do it next time" or "I'll do it tomorrow". I have so many things in my room I got because I wanted to try new things but I never considered my procrastination. A whole sketchbook and guitar are here just sitting in my room collecting dust even though I get alluring looks from them every day I never start doing the thing I want to do. I even have so many story and game ideas in my notes app that I never looked at again. I either just start doomscrolling on my phone or play videogames for hours until yet another day is over. I just realised I wasted my entire summer break AGAIN doing absolutely nothing. I can't do this anymore. I want to create, I want to inspire others, I want to actually DO SOMETHING. I would REALLY appreciate some advice right now because I can't stand this anymore. I can't stand myself anymore.