Bullshit I remember and hurts

A while ago in one of my bad days I was talking to someone that was at that time probably one of the most important persons in my life. I remember I was feeling like shit and I had been emotionally unstable for at least a week. So, out of the randomness that characterizes me, I started apologizing for nothing and stated that I remembered learning some things about life in primary school. She told me those were bullshit and I shouldn't guide myself by those. But every time I remember how those thoughts and opinions from others made me feel until I knew those were in fact false statements and harsh opinions, I can't help but think some of them might be true. Not in a literal way, but in the most emotional way. If I am feeling shitty and act some way I tend to judge myself by those false statements and that, I must say, that hurts. And it hurts bad. I continue to state those judgmental thoughts and opinions so a to remember everyone that they are NOT TRUE.

1) Crying means you are weak and a "little child". Therefor crying should be reduced to its minimum.
2) The words gay and lesbian are insults. Therefor you shouldn't be one of "those".
3) Other people's problems are more important than yours and should be always prioritized if you want to be a good friend.
4) If you study too much or like learning new stuff or like class periods more than break, you are a nerd and a bookworm, which is not good because no one likes nerds except from teachers.
5) It i completely fine to make other people or yourself feel bad if it will make people laugh.
6) If you are different than the mainstream, you have only a few friends and/or your friends are older, you will be excluded of groups and that is just normal and completely fine. But again, being excluded is bad and makes you a weirdo that no one likes.
7) Stating that someone or something bothers you is not right.
8) If you cannot deal with some people at your school, you should just change schools or change yourself, because the rest is always right.

Those are eight statements which I think should not be considered the standard way of a kids thinking and that are very harmful. Anyway I one had those a my "normal thoughts" and really believed I was the worst for being a nerd, for having a few older friends, for having different interests than the mainstream, for crying too much; I was the one who had to feel bad in order to make people laugh and like me, who had to keep to myself when someone bothered me, who shouldn't speak of their problems because other people have problems, who changed schools, because the rest, and I must say I don't believe this anymore, but the rest was always right.

Don't get me wrong, changing schools ended up being the best decision I could have ever made, but I wished my 'friends' hadn't been so happy because I left.