Complicated Relationship Advice Please!?

I have this girlfriend. Amazing. We never fight, we always compromise, she gives me everything, and we have everything in common. Almost like a female version of me. But right now I'm losing weight. I've went from 312lbs. to 293lbs. in a month. It's not stopping either. I'm eating right, working out at the gym 6 days a week, and plan on doing this for a year. I'll be skinny, muscular, and everything I ever wanted to be. But not everything... Why? Because back in college, I could never get a single girl to like me. I went to clubs, parties, and envied the skinny single life that the men I watched from the corner of those parties and clubs had. I wanted it bad. My confidence and insecurities were severely lowered. Now my girlfriend is fat. She's like 215lbs. I don't want to continue being with her when I become skinny because I'll be skinny, have fresh tight fit clothes, maybe a tribal tattoo on my shoulder, and be those same guys I've envied for so long. I don't want to be tied down at that point. I was never skinny and I'm not about to let being single, which is fun for outdoorsy clubby people, be robbed by perfect relationship. Bottom line is I wouldn't want a relationship at that point. I would like to be alone and do my own thing. Is that so wrong?