Im so angry and hurt please help!?

I work for a big corporation, but we are a small dept, and their are 3 of us who work on portfolios, I being the less experienced (they have about 10years ahead). My biggest issue is that one co-worker cannot stand me... why? I have no idea.. I have talked to her about it once (about 2wks) ago and she didnt say a word back to me, after I told her we are a team and I want us to be team players..she agreed and that was it. Well she'll try to do everything in her power to exclude me from meetings, or lunches with other depts or coworkers. Now the only co-worker that does like me seems to be excluding me as well, and although he bad mouths her he does everything to have lunch with her and just talk business with her. Im so hurt right now, they all went to lunch that she put together and once again they've excluded me because SHE organized it. Im hurt that my co-worker that does get along with me didnt bother telling me or inviting me.. and I've noticed he's been slowly excluding me as well. It's not a jealousy thing.. all im trying to do is move up and learn from them.. but they seem to not want that for me.. the female co-worker is so cynical all the time, and so negative and any chance she gets to throw anyone under the bus she does it.. and my other male co-worker knows this.. but since she's pretty sharp and smart and the bosses like her.. my male coworker would rather be around her than me. why cant we all just get along.. i've done nothing to her and she just doesnt like me for whatever reason. Just as a note, the female co-worker is a and she's short and stumpy..and not good looking but she is smart and sharp!! Basically, I want to know how to handle this situation without having to talk to anyone about it anymore??.. is it worth trying to hang out with them to look good??? looks like my male co-worker is just looking out for himself and what's convenient for him.. and since he knows she's somewhat liked by the bosses he's rather be ociated with her..