How to get not nessesairily ungrounded but less grounded?

Now I know what I did was wrong, I did weed and maybe abused it to much, im only 15 and my mom found my weed lying around and completely forgot about and I came home to ummm the house of hell haha... I am grounded for 2months (all summer) its like prison I guess you do your time and if you behave you get released early... I am not aloud to leave the house, go on my computer which I am on and not aloud to talk to certain people... I want atleast my computer back but dont know how to ask or convince them... I completely blew their trust in me I told them I stopped I quit and since then cant believe me im stuck here help please?