apps like 'focusme' are website blockers that i currently use. though take it with a grain of salt...the addict will always find a way around a blocker. it's mainly just a way to not be triggered like if you want to have 'safe search' on google. at the end of the day...these are just band aids...it always come from within you.
if you have access to a printer, i'd suggest just printing the lessons and to separate yourself from the situation. the trigger, your computer, seems to be causing you stress. if you can isolate the trigger, then this may help you gain traction. but again...take it with a grain of salt...it's not the computer that is the issue...and triggers are everywhere. it's the emotional management skills that need to be learned.