You sound a lot like myself. I've been told many of the same
things, and I've been in a situation like that for awhile. Let me
share with you what I've learned. 
Do nice guys finish last? I hope not! 
Dating in secondary school is just, well, weird. It's
hard to know what to do, how to act, and all those other
things.Other people are feeling the same way, although they don't
show it. Something that I try to believe is that everything happens
for a reason. It's important, if you believe that, to try and keep
that in mind and to see the positive, even though you aren't happy
with the girl situation at the moment.
The one thing I would tell you NOT to do is to change how you are
acting so you are more like those other guys. For one thing, I
think the first rule of dating and building relationships is to be
yourself. If you do change and start dating someone, how long do
you think you will be able to keep that act up? Secondly, everyone
in your clique knows how you are and how you act, and if you change
now it's going to be very noticeable, and will probably be more of
a turn-off than anything else. Lastly, you are who you are, and
deep down inside you can't change that. You said you felt
uncomfortable with that act, and that is the reason why. It does no
good to change who you are for other people. Life has a way of
balancing itself out, and I think sooner rather than later things
will work out for you.
Cheers
