Maybe just immature rather than shallow. It is hard to break up with someone who you know will be hurt by it. Procrastinating to avoid causing pain only makes things worse, yet it is quite tempting. Especially for a freaking 18 year-old.
Part of the danger of getting into a serious, sexual relationship at a young age is that while you might be ready, the other person easily might not be. I guess that’s life though, no guarantees.
Don´t worry, condoms and the pill are always used.
As for the Spanish guy thing, though, I admit that most of them are really hot; however (and I´m not saying this is all of them, just the ones I´ve had extended conversations with) many seem to be really stuck up. And I currently am in Spain, sitting in a little internet cafe so that my brother can check his email.
Well, you can enjoy looking at them anyway. Yow. 
I know I’m jumping on the bandwagon here, but, do you realise that in some countries (such as Aus, where I am), many 17 year olds have moved out of home, and are working or at uni? And can drive? Being 17 here is effectively the same as being an adult, except they can’t drink in public, gamble in public, etc.
To Monica, I’m sorry your BF broke up with you. At least now you don’t have to pine for him while you’re away now. 