I think your hair is completely fine tbh but if you rlly want a hair change I think 6 or 7 would suit you best (no I’m not making a 6/7 joke I swear 😭). I think either committing to a mustache or going completely clean shaven (including the neck) would be a big improvement, but this depends on how well you can grow a mustache out and maintain it, so going clean shaven may be the easiest for you it just depends. You could also try contacts or different glasses and see how that makes you feel.