I was in that cycle not too long ago. It took some planning in advance; shop for water, Gatorade, buy or fix soup or other easy to fix/digest foods, ice cream in case you get sugar cravings, and take care of everything that needs to be done before your next day 1. Stay home. Just stay. Do not leave. That was my focus, to break the routine, get through the first few days, and avoid all triggers. I didn't answer my phone, call anyone, just R & R with SR.
Don't give up, it's not hopeless, it's just hard.