I don't have specific point-by-point advice for you like Gala Girl gave you, but it definitely sounds like you owe it to yourself to do some soul-searching and find out what makes YOU tick. Since I don't know you, I can't tell you what areas you need to work on, but you seem pretty self-aware to begin with. So build on what you already know, and figure out why you feel so "old". You're only 30! I'm going to turn 42 in a few months and I like myself better than I did when I was 24! I sometimes wish I could get back the past 20 years and apply the experience I've gained, but in no way would I want to be 21 again just so I could feel more attractive as a dating partner.
I don't know if that helps, but those are the thoughts I had after reading your posts.