Sorry it is a frustrating time for you Maybe I am way off base but from what i can read, it sounds to me like your mom has set some healthy boundaries and is enforcing the consequences of not respecting them. I think this is probably a good thing for her recovery and for yours. It may help you to better understand her perspective if you spend some time reading in the "friends and family of" forums. Maybe if You can talk with you mom and assure her that you understand and respect her perspective then it may be possible that she could define the requirements nd timeline for returning the computer and phone. No guarantees though as it is obviously her call.
Good news is that many of us moldy oldies were able to accomplish great things without cell phones and computers!
I know times have changed but it is still possible so please do not let this setback become an excuse. You can do this. Keep getting better and thank your mom for her contribution to that process.
Truly wishing you all the best.