How much hard work really pays off

So I've come home for the summer to skinny friends. At least three of my friends have lost weight, enough weight that people notice. And I'm pissed! Wanna know why, because I have be eating healthy and excersising for 5 months. I lost 20 pounds, but somehow gained 10 back around exams, just in time to come home for the summer and not really look any different from when I left. So of course my hard work is absolutely nothing. And what annoys me even more is that the people who have lost weight havent lost it because they have been working hard, theyve lost it because either they have men in their life who stress them out, they decide not to eat just because they are stressed or they dont really have the money to eat all the time. How unfair. I guess I should be happy that I'm healthy and will be for the long run but not right now I'm not. I wanted results and that is why I was working so hard for so long. And the fact that 10 pounds crept up on me right after formal makes me sooooo angry. But oh well I'm still working at it and hopefully I'll have dropped another 20 pounds in the next 5 months.