It might seem a little counterintuitive to post this in a dating thread, but as much as people joke about (or have real concerns about) being "forever alone" on GAF, there's really nothing wrong with being alone unless you *tell* yourself that you should feel bad for being alone. A variety of societal pressures and influences have convinced people that coupling up should be one of their largest priorities in life, that you can't really feel "complete" until you're with someone all of the time, and so on. I would challenge you to re-frame what it means to be alone to something more positive and, in my opinion, more grounded in reality.
Brent Smith does a great job of tackling this subject here. Essentially, it's okay to just relax about the whole thing. Don't beat yourself up constantly and become lost in what could have been, and don't convince yourself that women and friends are a scarce resource that you have to cling to in order to not lose your social life forever. It's okay to take some time to reflect on what happened and to take responsibility for your actions, but it's more important to see what happened as an
opportunity to live an even better life.
Take advantage of the tremendous opportunities that being single offers. You now have plenty of time to focus on yourself. Like people have said countless times before, you can start working out more aggressively, you can pursue your passions in life, and you can push yourself out of your comfort zone and try new things. Take the time to learn to love life again *without* needing things from other people to feel validated. If you do this work on yourself and fight any impulses to withdraw from the world, you will naturally pull in plenty of people.
Above all else, don't convince yourself that you need someone else to complete your life. You're already a wonderful, complete human being, and things that you perceive to be personal shortcomings are just opportunities for you to grow and become even better.