Why do I always get in trouble at school ?

Like almost everyday I end up in the principal's office. I'm in 7th grade and the last time I went to the principal's office was like a day before school ended and my principal said "You keep lying straight to my face and I don't want you to get good at lying, I also don't want to start 8th grade with you being trouble all the time"( i skipped class a lot and i just didn't participate in activities the whole grade was supposed to do, and a bunch of other stuff ) i dont know why i always do these things. I know they are wrong but i still do them anyway. I think im sort of depressed.. ( i cut myself but i dont do it a lot anymore because its summer and i wanna wear short sleeves) do any of you get in trouble a lot ?