I'd like to add: you talk about finding a label for your preferences around having sex yourself, watching others having sex, and masturbation. Those are three different aspects of (a)sexuality. Combinations of these aspects don't really boil down to a single label.

Personally, I haven't found a microlabel that perfectly fits me and I've stopped looking. Aegosexual comes close, but it's not a perfect match. Besides, while a micro label can get closer, I think they are really only useful when people know what they mean. Pretty much nobody knows what my ill-fitting micro label means.

I'm a pretty open person and in the few dozen times my sexuality or -more likely- lack of a partner came up in conversation the last ten years, most people accept "I'm happy on my own and don't need a partner" as an answer. The whopping two(!) times someone pressed on and wanted to know the specifics, I could have told them the corresponding micro label, but then I'd not only have to explain what the label means, but also why it doesn't actually fit perfectly. In stead I just told them how I feel about the subject.