The idea of you being mocked for being 28 and single is pretty bad. I'm 38 and in the process of being dumped by what I thought was the love of my life. Hurts like everything, but I know I will be fine. And Guess what.... YOU will be fine too.
Life is all about experiences. Each experience makes you a stronger, more well rounded person with a much richer life. Even the bad experiences do this.
As a professional, you are obviously NOT retarded. and there is not a single person on earth that is worthless. It sounds like you have a good bit of passion, openess, and many other good things to offer; both to your friends and the people around you AND to any potential boyfried. If any of those people don't appreciate and respect who you are and what you offer, then surround yourself with different people.
Now, head up, chest out, shoulders back, eyes wide open. Enjoy your world. Even with the bad things.... it's still a wonderful place.
This above all else... to thine own self, be true.