I don't think having sex will cure your loneliness - and it will quite likely make you feel worse - when you realize that people have engaged you for sex, but not for YOU. Try finding a partner in life, whom you truly love, and with whom you can share everything.
Oh, I'm not even seriously entertaining the idea of "playing the field." That would require the active cooperation of at least one member of the other major gender, and I'm... comfortable with celibacy. I mean strict celibacy, too, not just sexlessness. It has its advantages, in a greater amount of disposable income, for one. ;-) For another, I can spend time taking care of my parents. So, I'm arguing this not to defend promiscuity, but rather more as a devil's advocate, with the thoughts I have fought myself.
One issue is attractiveness. Even a random act of sex requires said active cooperation, and that in itself is some validation of my worth. Being frank, being attractive to other humans is a nice thing. It makes us feel good when we know we're wanted. Even if it is only for a short while...
Of course, after the disgust subsides, the emptiness must be filled, and that's usually with another short-term relationship. So, once one's started down that road, it's difficult to get off it; finding something other than a short-term sexual relationship to fill one's soul rapidly is a challenge.
The other question is related; if everybody else is having it, why can't I? Forming that question leads to serious questions of one's own worth, as noted above.
Thanks for this discussion.