Quietude, once again I'll offer a different perspective from the others above. Here's a 3 point response for the condition you're in.
First of all, know that you're loved by God, and that's true whether you believe it or not. And since Jesus himself said that knowing and loving the Lord is the most important thing in life, it's no small matter to disregard. Whether you go through life as a loner or socialite, I'd encourage you to focus on the one most significant relationship that you can obtain by your own free will and action. I know that for me and other Christians, having that close relationship right gives peace of mind and love in the heart - something that we all need and something that helps us maneuver through life better.
Second, I can relate to the feeling of being a loner too, since I have spent much of my life being one - not by choice, but moreso by career factors and other circumstances. When I reflect on the best times of my life though, they usually entail doing things with other people. No doubt, my social time with others has brought me more fun in sharing experiences, more interesting conversations, and more bonding friendships than even my best times alone. For that reason, I believe that we're all better off recognizing our innate need for people and relationships. My own father and a couple of friends of mine reject this premise, and have gone through their whole lives intentionally avoiding friendships, social affairs, and even family relationships. It's a sad choice though, since the most important, rewarding, lasting thing in life is love, and that only comes from relationships. One can make it through life as a loner all right, but there's little defending it as a more fun, enriching, or memorable life to pursue. Thus, while some of us lead the loner path at times, I think it prudent for us to recognize it as a temporary diversion from the path we're designed for - something to overcome by taking active steps. For me, that means forcing myself to go out to places where I can meet people and to be assertive enough to strike up conversations with strangers. It also means valuing every new contact I make and friendship I have by staying in touch and paying regular visits. If you're settled down in a town, I think the best way to meet friendly people who will quickly accept you is at a good Christian church. There, you can quickly build a social circle of worthwhile relationships by participating in their small group studies, community volunteer programs, and more. A recreational or social club might give you this too, but I've found that many clubs are like high school, having their clicks already in place, and leaving it hard for a newbie to break in. A (good) Christian church couldn't be more different. There, the members want newbies to feel welcomed and want them to be part of the church family. You just can't find a more relationship forming environment, and you needn't be a believer to show up and be welcomed there. Finally, on this point of seeking relationships, I'd like to share one more Christian perspective that I've just recently discovered - what we'll likely experience right after we die. Whether you're a spiritual believer or not, the scientific evidence for a human soul is becoming substantial. This is being revealed more now through books and videos on near death experiences, with millions of people claiming to have had them. One of the shared reports from various NDE witnesses is a warm welcoming in heaven to those first appearing there - by known friends, family, and past encounters. Most Christian pastors and theologians would deem this consistent with heaven too - that we'll be reunited with (believing) loved ones from our life here. In other words, the relationships we build in this short, temporary life may determine the ones we'll have in the future eternal life.
Thirdly, I offer a worthwhile solution to all single people seeking a mate in life who haven't succeeded by chance encounters: the online dating sites. I feel like an expert with them after plying dozens of them over the past 30 years (starting before the internet actually). And while I have not yet found my Miss Right, I know a few things worth mentioning in its defense: 1) You can increase your selection pool and potential encounters from dozens a year to hundreds of thousands, 2) There's a large majority of the girls looking for a serious long term relationship, and 3) searching the profiles can be both fun and provide optimism. I personally subscribe (and pay) to 5 different date sites at a time, giving me more prospects to consider than I could ever see or meet otherwise in a lifetime. It is a simple, efficient process, and I enjoy the constant interaction that the sites give me. For a single lonely guy, I definately recommend you put some money into the online dating game. It's particularly a viable pursuit for someone who's shy or introverted.
So, there's my 2 cents (or 2 hours') worth. I hope that encourages and motivates you.