Work on your body and improve your confidence. If the changes you see in your body ignite something in you go with it. Get in good shape and become proud of your body. It will be a great source of confidence.
Improve your social skills. When you are ready to go out with your friends don't think you have to do anything right away. Try to find friends who are good with girls and you are comfortable around them and when girls will come around try to act "as if" you've been there before. Just follow the lead of your friends.
Make a friend. Before you meet a girl to hook up with you'll probably meet a girl who likes you as a friend. Hang out with her, see if it doesn't help with your attitude and your confidence. Don't worry about fucking her.
Do those 3 things and a girl will come to you. Don't force the issue, but don't pass on anymore opportunities. When you know a girl likes you pay attention to her and all you have to do is act interested and let them do the work. it is really that simple. But you gotta close the Deal! At some point you have to initiate the first kiss and when it comes take your time and don't miss lol.
I was 18 when i had my first kiss, i fucked up by telling the girl it was my first kiss in the middle of the kiss and then getting embarrassed about it but oh well. SHE WAS SO FUCKING HOT. it was easy, she told my friend who was a girl that she liked me and i asked the friend for her phone #, called the girl and went from there. so I did had to grab my balls at some point. Good luck bro,. I don't consider you a loser.