An easy way to have confidence in yourself is to know that you are "the shit", think your all that, because as you've said your ripped and good looking. Compare yourself to the other guys around you and notice how much better you are than them but don't put them down or anything literally. This worked for me in a way, I was like you, shy and had no confidence, then I slowly compared myself to other guys and noticed that most of them looked pretty ugly and were out of shape (I look pretty good and have a athletic build, still building it up now). I realized how much better I looked visual than these other guys and that already boosted my confidence, don't make fun of the other guys though.
After I made that internal change, I noticed girls started to look at me more and found me more attractive. You know how some guys count how many times they get checked out by girls, just last night I got about 4 from different girls that were average to good looking, didn't count the looks I got from girls that I wasn't interested in. Still haven't found the right girl to be my girlfriend though.
I remember a similar phase like this happening in high school, when I had high confidence during a year, I was one of the top asian guys of my grade to date, so many girls were checking me out. Then a year later, my grades went down, I felt like shit and my friends feeling low for similar reasons made me feel low and my confidence went down, therefore making less girls attracted to me. I also wasn't driving and didn't have a car like some of the other guys, I didn't come from a rich family that bought you a car when you got your license (the school I went to was full of rich kids, I came from a lower middle class family.). Not being able to drive, my confidence went down even more.
Also when you do get a girlfriend, lie about it, say you first lost it sometime when you were 18 or 19 and you were drunk at a house party. You woke up in the morning in bed with some random girl and that was it. You can tell her the truth later on if you build up more trust and said you didn't want to be embarrassed to tell her that you were a virgin. Or you can say your waiting for someone your going to marry to lose your virginity to.
The good thing about saying that you lost it at a house party drunk is that you can change it to say you definitely lost it or maybe you lost it. Its the gray area.