You should be able to get into your zone without having to offer a constant stream of meaningless reassurances.

I would say in terms of keeping in touch (with anyone), a scheduled phone call (with a calendar alert and/or alarm) is a good way to catch up without relying on your memory or time keeping skills. And if you are having a mental health day, a quick text to reschedule should be acceptable (as long as it's not every time).