I wouldn't be too tied down with your ADHD diagnosis, it may have helped you understand why you struggle with things, but even without that, just accept yourself and what you do. I tend to jump around with hobbies as well, acrylic pouring, Chinese calligraphy, yoga, woodwork are just a few which I've started and bought loads of material, but not mastered or touched after a while. Even blogging, I do less of it now, and am lucky if I do a post a week. I see it as a drive for me to restart those hobbies again and stop procrastination...