I need to learn to be a good friend

Today was a terrible day, I couldn't say anything and I looked like a little RAT, I'm a terrible person, easily discarded. And I don't know when the compliments or nice words dedicated to me are real or just have an expiration date. 

I have no idea why I was born avoidant and I don't know how to express myself clearly and I'm ALWAYS annoying others and being "insufferable" (my BEST FRIEND's words) and I don't even know how I can be a better person, keeping in mind that all I know is to apologize and try to be at least a little nice so that no one hates me.