I need some advice!

O.k. I’ve been in love with the same girl for the last 6 years or so, she is a good person, she lives in France as she attends college there, we only see each other during the summer, we’ve never had a formal relationship for obvious reasons but there’s been romance all these years (specially from me towards her). Every summer is the same story, we date we kiss and all the stuff but when she feels she is going to commit emotionally to me, she does something so send my heart to the trash can, she leaves, writes a couple of e-mails and then everything is fine again. I’m dating a wonderful person now, (barely 2 weeks) she is awesome, smart, sweet, she is a great girl, but now the other one just called me 5 minutes ago to let me know that she is here, I do want to see her but I don’t know what to do, I don’t want to ruin my current relationship (in the past, I’ve been alone so I didn’t care what could happen at the end of the summer) but now, the person I’m with deserves the best guy in the world and I’m trying so hard to become that person I just don’t want to ruin what I have now. But my heart wants to see the other girl, I just don’t know what to do. A part of me tells me that she likes to use me… Should I tell the girl I’m with the whole story? I’m so confused, I have this horrible feeling inside my chest now (is that love what I’m feeling?) I’ve suffered way too much because of this, its consuming me, It had even changed me a lot, form the “all you need is love” kind of person to the “stay away from me I don’t want to hurt you” type. I’ve tried to get over this but I just can’t… I need some advice, or just some comfort… thank you all