Everyone gets lonely sometimes. Especially around weekends. And holiday season. When you're at home without any plans. When all your friends have their own plans. When you wish you had something interesting to do, more friends to hang out with, more people to talk to, to party with. When you wish you didn't have to go to bed so early.
This is normal. It passes. Just concentrate on your hobbies, your likes, what excites you. Do what you like to do - read books; watch movies; go to plays, concerts, performances, screenings, seminars; travel; take a walk; take photos; play a sport, games, etc. You will meet people. Talk about common interests. Stay in touch. Over time, you'll gather like minded souls to you. Don't worry about the intermittent lonesome days/nights.
While I'm on the subject, I remember one of my psychology professors back in college telling our class about depression and that even though more men than women suffer from depression, men are better able to cope with it, as society allows men more freedom to do things that might counter depression. For example, a man who's feeling down can always go out for a late night movie by himself. Not so for women as much.