eating disorder?????

I’ve never had any problems eating before but in the last couple months there have been days where i don’t eat anything all day even though i’m hungry and then there’s days where i eat fine. all my friends get mad at me when i don’t eat and say i’m anorexic. i’m 5’1 and 130 Ibs. I work out a lot and have a lot of muscle. My weight also fluctuates a lot because of it. I once lost 4 pounds in 5 days because of fasting.