Background disclaimer: Since I was 16, I've never been single for longer than 3 months. Married the first girl I dated when I turned 18, divorced at 26 (that makes a decade-long relationship... that's more than a third of my life, ugh), dated a couple more girls briefly, and am now in a relationship that I've been in for a year and a half (and I plan on it being my last romantic relationship).
I can't give you much advice on being single, but I can offer some advice about your possible future with relationships.
Whether you've been in a relationship for a month, a year, or a decade, a relationship is work, and it will never stop being work. So yeah, even for die-hard long-term monogamists like myself, there are times where I feel like I just don't have it in me to maintain a relationship. I'm lucky enough to be with someone who understands my various neuroses, and the times when I'm having a bad day week month require a lot of patience on her end; that kind of commitment to me is returned with me not taking her for granted, and not ignoring her needs. I will tell you this - never stick around in a relationship you don't want to be in or doesn't make you happy. It's better to remain single forever than to mire yourself in a partnership that makes both of you miserable. The end of my marriage was basically both of us trying to salvage something that was irreparable, and being miserable in the process.
If you do find a special someone that you want to be with, and they want to be with you, some tips - communicate, be honest, and prepare to make compromises. If both of you do this, your relationship will be wonderful. If neither of you do this, your relationship will be terrible.
My advice to you, summarized: ignore society's expectations, live the life you want to live, cultivate friendships, and keep an open heart. Don't be afraid to get in relationships, but don't get in relationships just because you feel like you're expected to. If you find someone who you dig and digs you, you'll both find a way to be together and make it work. If I, as a manic-depressive introvert who may or may not be mildly autistic, can maintain a relationship, I know you can, too.