I won't tell you that looks don't matter because unfortunately they do, in our society and this day and age. If weight is a huge concern, have you tried to lose it? That kind really change a person's appearance drastically (e.g. face shape) and help with one's health too.

Also, this is a pretty radical measure but if you are really unhappy with your physical appearance you may want to look into plastic surgery. This is less of a deal here in Asia (especially South Korea) as compared to the West. If I remember correctly, back in 2012 approximately 20% of South Korean women were reported to have had some work done. There are a lot of girls (and guys) who gain that much more confidence post-surgery. Personally I see nothing wrong with paying to improve one's looks, but of course this is highly subjective so I'm just trying it out there as a point for consideration.

Wishing you all the best