I didn't gain THAT much ;-)

LOL, no. Hell no. We shouldn't trust it. :') And it's an individual person's fault if they get "so fat".

As a general rule you should trust whatever you think it's logical or senseful. That case in particular is very subjective to each individual and to each manner of thinking, and even to each one's habits or metabolism. You can extract something from it, though: Telling yourself you're beautiful isn't such a bad advice. I have had problems with my looks in the past (even though beeing a male), and it's not very uncommon from teenager to have the same problems I had.

However, what is there is, overall, very poor in substance. And that's the first thing you should notice without the help of anyone else. Even if poor substance doesn't necessarily mean it's wrong, it usualy means it's not really apt to be considered worthy of notice.

I rarely give advice, and I rarely accept advice. I am the best at deciding what I should do, how I should think, and so forth, for I am the only one who knows myself truly.