I am in HUGE trouble. Help?!?

I am not a bad person. I am nice and kind, but I have got into a lot of trouble recently. I have had a lot of givebacks>7 (my schools punishment from things tiny bad that make u miss recess and many = detention). I already have a detention (most STUPID reason) and I had to be talked to today. The dean of my grade said if I get another giveback by winter break I get a detention, but right after we talked I got a detention in hockey for putting a cup holder as a friendly joke on my friend's head. ISN'T THAT CRAZY?!?!? Now... I got a detention right after they said if i get a giveback I will get a detention... so what will happen if I get a detention? SUSPENSION?!?!?!? THat cant happen. I am insanely kind person (won j.r bean award in 2 yrs ago>most kind person basically). Also, My hockey coach from school made me sit in the cold for 1.5hrs with nothing but a t-shirt and some pants (i didnt bring anything else). How do you tell my parents without them exploding? How do I NOT get a detention (i shouldn't get one), how do I tell the dean of my grade this? What do you think will happen (Detention, Suspension, etc.) I am a 7th grader in a private NY school