I think im depressed. am i ?

im 16and i used to live in houston my whole life and about 2 years ago we had to move to mexico.it was a huge change in a short amount of time it happend so quick during summer (1 month)..and i just felt really bad..now in this school year is pretty good , i have my friends and everything but still feel really depresed and feel like something is missing... i just feel like why would someone like me.even though people say im pretty and why am i single. i just dont feel that im good enough for anybody...and i look at the pics that my friends fron houston put up on myspace and get even more sad cause that should have been my life. instead of being here..any adive for me