I'm not trying to trivialize what you're saying, but 
I know what you mean . I'm 23 years old, I've never had a boyfriend, I've never gone on a date, I've had one person tell me he liked me, but by the time we discussed this, he only saw me as a friend/sister. My friends from freshman year of college are all married, engaged, or seriously involved with someone and on the verge of engagement. I try and put on a brave face about not having a boyfriend with most of my friends (there are a few I can talk to about it)...I feel, as you do, that I'm always meant to be the "friend" to all the guys that I am attracted to. I'm super shy, so I don't even have the guts to talk to someone I like and TELL them I like them. It's something I need to work on.
Hang in there....the right person is out there for you somewhere....and until you meet him, we can always commiserate together here on GC.