i did that too in my undergrad i created separate spaces for myself in my apartment if im at my desk i physically turn the phone off not just turn off the ringer or notifications then when im done and go back to the couch phone can go back on i had the same rule for myself studying at the library phone literally turned off   with my adhd i transition around so much that i get distracted waiting for the phone to turn back on if i know that will happen then its like a flag for me to direct what little focus i have back to what needs to be done