Why have I been getting annoyed so easily lately?

I don't know why. So many things have just been annoying me in general. My mom's quirks annoy me, if my friend talks to my brother's friend (cuz they used to like each other), I just want to yell at her and tell her to leave him alone and get out of our life, I gave one of my other friends counsel on a matter but she kinda ignored it and is still doing something so I'm really annoyed at that..I don't know, I'm 15 but I seem to be getting upset/annoyed with people so easily lately, and sometimes people just piss me off and idk why. I'm not normally like this.