Well, first of all, you are going on about the unfairness of his being with someone else, when you don't even know that that is the case. Right? Wasn't this just a speculation from somebody?
Second, the fact that you are not with someone at the moment has absolutely NO predictive value in terms of the likelihood you will meet someone with whom you want to share your life.
Third, there are some big-time advantages to being single that you should not overlook, either. You are free to do what you want, when you want it. My friends who stayed single go on fantastic vacations that their colleagues with families cannot afford. I'm not suggesting one is "better" than the other, just that usually there's a bit of envy on both sides of the marriage divide.
My suggestion is that you work on building a fantastic, interesting, fulfilling life for yourself. Happy, interested, engaged people (I'm not talking romantic engagement--I'm talking about being engaged in life) ultimately attract friends and partners who admire those qualities.