Stop spending so much money trying to impress other people. It's not worth it. Stop relying on other people's approval of you to be happy. Who gives a about the people who find you "short". Seriously. I would question the -ness of anyone who would call a 5'9" guy as someone short. I don't believe for a second that going from 5'9" to 6' would be that much of a difference. You list two improvements:
1) Confidence - You do realize that this is all in your head, right? If you really need confidence, you just have to think that you're taller than you really are. Also deriving your confidence from your height is pretty sad. That's because that's not really something to proud of. You should get your confidence from doing great things and getting achievements. When I ask about someone, I don't ask, "Oh, what's his height?" I ask, what does he do or what has he done? People don't care about your height as much as you do or as much as you think they do.
2) Attention from women - You're not getting attention from women at 5'9"? Really? Dude, at 5'9", pretty girls have been talking to me left and right. I admit that it wasn't as much when I was 5'5"-5'6". But you're complaining about being 5'9"? You're doing something else wrong in your life if you can't get quality women at 5'9". I mean, granted, I drive expensive cars. But being in debt is what drives women away, unless you plan on only doing one-night stands for the rest of your life. And as someone who's done that before, I can tell you that eventually it gets old and leaves you feeling empty. It's much more fulfilling to have a deep relationship with one great woman. And by the time you're in your late 20s, having money is way more impressive than being 3" taller. Only thing you'll probably be left out on here is girls who are taller than 5'9" will probably not date you as well as superficial girls who only want to date 6' tall guys. But who cares about that those minority of girls. Let's pretend that you are a white guy who wants to date asian girls. There are a lot of asian girls who only want to date asian guys. Would you get a surgery to become asian? NO! You find the asian girls who do like white guys. So don't don't don't do this surgery for "attention from women". If you want attention from women, get a puppy. Seriously. Get a cute puppy. My puppy gets me a lot of attention from women on the street.
It's not my place to tell you what to do. But as someone who has been through this surgery, I'd say with 100% confidence that this surgery is not worth going into debt for. Your legs will look disproportional. Certain sex positions will be very hard to do because you're not as flexible anymore. I honestly have trouble doing missionary position now. It hurts to have normal sex! It's pretty messed up. My sports skills now suck. My stamina is crap compared to before. I probably shortened my lifespan doing this surgery. I missed out on a lot of fun events and trips with friends because I was in a wheelchair for half a year. I mean, yes, being taller makes me feel better, but there's so many downsides to this surgery as well that puts me in a position to not fully recommend it. And if I added "debt" to one of the downsides, I'd say that it's not worth it anymore. If the pains in my legs don't go away, then I'd also say it's not worth it anymore even if the surgery was free. Keep in mind that I got my surgery around the age that you plan getting it. So don't think these things that happened to me won't happen to you. Even if there's only a small chance of it happening, it's not worth it to gamble your legs like that.