awe, my wittle baby's growing up!!! CONGRATS!!! and i LOVE how you call her the "subject" lmao!
and speg, IMO you are a very attractive guy! As for your unsureness of whether your ex thinks you're attractive or not, here's what i have to say: no matter how shallow it seems, people only date people they find attractive. It's natural selection, and nature's way. Just like butterflies. The female looks for a male that is the most brightly colored, most symetrical. This is so she will have beautiful babies. In a way, subconsciously, humans work the same way. I think shallowness is not dating someone because they're ugly, but when you want someone who is attractive, it's just natural. Having said that, your ex obviously found you attractive, otherwise she wouldn't have started dating you in the first place. That's it. don't think about it any other way, and don't say 'well i don't know if she really found me attractive', because frankly, that doesn't matter... out of sight, out of mind. You do have to have more confidence. Just get it set in your mind that every girl finds you attractive, but not in a pricky kinda way. Girls love a guy with confidence, but remember there is a difference between confidence and cockiness...
As for your girl who is "only a friend", i was going to suggest trying to flirt with her, but after reading that she's insanely hot for you, i suggest otherwise... That would just be mean. Do you go out to bars and clubs? if so, select a "subject" (lmao!), and think to yourself "ok this is just for practice, it's not going to go anywhere, and i don't expect her to go for me". Once you get in that mindframe, it should be a piece of cake! you should attempt to talk to a few girls this way, until you feel confident to talk to someone you're really interested in.