Basically my ex fiancŽ did dope and I had a little of it now and again, but then when we broke up I found more of my mates do it too. As I enjoyed a little smoke now and again I bought my own stuff e.g a grinder and some weed. For 3 weeks I was buying my own and hiding it at home. Ä°t was never a serious addiction just a recreational activity. One day my dad and sister go shopping leaving me with my mum but I go out on my paper round leaving her on her own. My grinder which contains my weed was in my room in my tin which was in my handbag. Ä°ve been grounded 1 month now and the first weeks I was ill and got loads of treats.iv run out of jobs to do about the house the only thing I do now is my paper round once a week. But now I may have completely ****ed up as staying in doors makes me depressed I get depressed I self-harm which I have done. Any Ä°deas ?

Two concerns here, the smoking (marijuana, I assume) and the self harming.
Have you ever sought help for these things, I think you should. Do your parents know about the self harming? As a parent, I would be very concerned about that.
Have you self harmed during this grounding or are you speaking of the past?
And have you stopped the smoking?
Regaining you parents trust will not be a quick thing. You are going to have to prove that you can be trusted, by keeping your word, staying away from the weed, and the people in your life who influence you to smoke.
Do your chores and be responsible with your school work.
I think you as the child do not want to disappoint your parents and parents want to know that their children grow up healthy and strong and make good choices for themselves. Weed is not a good choice. And the self harming concerns me.
As for the staying in and becoming depressed, depending on where you are and the season are there chores that you can do outside?
Helping with the lawn, or perhaps have your Mom pick out a small place in the yard that you can turn into a flower garden for her, that will take some time to do and get you outside.
And when you least expect it, a bouquet of pretty flowers you her to enjoy.
Working the soil and watching things grow from it is very enjoyable and rewarding, if that is an option?