Why the wrong person?

So this has been on my mind for a while now and I just have to ask.  I'm 27 and in college working on my major (I almost have my associates yay).  This last term I met a really great person in a sociology class.  We had a group project and he asked to join the group I was in and me and the other person at the time agreed and eventually we had another person join the group.  I was made leader for whatever reason and couldn't say no since everyone seemed into it.  Because of that I was able to get to know this great person and we soon became friends and I noticed myself falling for him.  I have all these wondeful feelings inside and I always feel so happy to just hear from him or anything.  I believe people come into our lives for a reason and I don't know why this person and with these feelings yet.  These feelings are just so different from what I've felt before for anyone else.  Around New Yr's last yr I asked him and a bunch of other friends if they were doing anything and he responded and said he was going to a gathering thing at his girlfriends house.  I was so crushed and just cried for days and even though I knew this I still had these feelings.  We lost touch for a little bit but then the new term started and he started texting to just say hi and all that.  He's still with someone now and I still have these wonderful feelings.  I just don't know why this person and these feelings were brought into my life.  On the one hand I feel really special with them and on the other I feel awful because I can't do anything about them. :( I'm mostly just venting but would love a response on anyone's thoughts.