Is your brother aware of how you are not managing? I agree with others here. Take a break. Live offsite. Get another person in to help run the business. They may even take a pay cut in return for a place to live. Access 24/7 is an impossible task for any person in the long term.

Our bodies/mind are very smart. If you don't take some action now your body/mind will do it for you.

Please take steps now to deal with things.