Well from what you described, I like you already, since I happen to like women from that part of the world.
Sadly, though, guys around your age are still caught on having only skinny girls, and ignore overweight girls, regardless if their face is very pretty or if they have great personalities. Still, it's not hopeless, just get out there more, be friendly to everyone. Eventually you'll find a guy who sees you attractive and will ask you out.
Anyone can lose weight with a good diet and exercise it just takes the mindset of I can do it. Calories burned + good diet = Losing weight.
With that said honestly I doubt its your weight I know plenty of big girls that get plenty of guys. Try doing things that boost your confidence. Go do girlie things, shopping for new clothes, spend some time at the gym. Guys will really notice the effort.
it sounds like you just may need to assert yourself more as a sexual being, really show guys that you are interested in being in a relationship...of course the difference between this and desperation are a fine line