Let me start off by saying this, what I think about a situation like this is that what you've done in the past doesn't really matter now. I'm the same year as you, and I had a mutual(?) crush on a girl in freshman year, but I was too scared to confess so we both slowly drifted. As time went on, I stopped caring as much and we both drifted until I started talking to her again this year. Did she remember I had a crush on her? Yeah, but it's not like that matters now. What I'm trying to say is, forget that crush you had on her and what effect it had before, cause that really isn't helping you currently.

From what I've read in your post, you need to branch out more. Whenever i talk with somebody, if their response is "ok", or "i dont know", the topic is dead and I move on. The response honestly doesn't matter, you just need to progress the conversation until you've hit a point where you can contribute.

Of course, all this advice could sound like crap, and I honestly don't know if it'll work for you. But if there was one thing I'd let you know, it's probably to just be yourself. A lot of people say this advice is crap, but it's really not if you expand it a little more. Being yourself leads you to find friends that really enjoy your presence, if that girl doesn't like you, that's fine. People change, they're never constant. Don't have a lot of friends because of who you "really" are? Then change yourself. Get out more, loosen up, no one likes seriousness 24/7.

All I'm trying to say is, be comfortable with yourself before you try to get comfortable with someone else. You say you're not secure with your ability to socialize, then you need to work on that first. Get to a point where you're satisfied, then go for the friendship.

And no. You're not a loser. No one's a loser. You just need to see yourself in a new light and be proud of who you are.