Determine that romantic pursuits are a waste of time and dedicate yourself to athletics, reading, board games, and professional advancement.
Maybe it's different for you, but if I didn't have a SO I'd be extremely lonely and probably much more depressed than I am now, even if I had a successful life.
I have housemates, as it stands. I generally work 44 hours a week, alongside taking about 6 hours of class, studying, and working out. The weekends are for taking care of classwork and my second job. It's a matter partly of introverted disposition, partly of convenience, that I socialize with a relatively small group of people. Experiences in undergrad produced a great amount of... let's say confusion that consumed considerable mental and emotional energy. From that standpoint, it's not worth breaking out of my selected social territory at this point in life just to complicate emotions. From that standpoint, it becomes amusing to see the extent to which other friends of mine might either whine about not having been laid since X, or about failed attempts at romance/releasing reproductive urges. Asexual scholarship is far more comfortable.