I am so tired of dealing with my two best friends for 3 years

So recently I have been feeling like I do not want anything to do with my two best friends anymore because one of them keeps on switching up on me, like at one time they were nice and then another time they were mean. My other best friend keeps on saying that they are not going to be my friend anymore and then after they leave me they come back, and then they will say that they are not going to be my friend anymore again. At this point I do not want anything to do with my two best friends.