You can’t break your leg and run a marathon the next day.
Say you were a marathon runner. If one day you broke your leg, you would certainly not expect yourself to be able to run marathons for a while. In fact, you would have to take very small steps and work consistently to get your leg back to where it was, where you could then run marathons again. It would be foolish to think you could break your leg and then run a marathon the next day.
With our mental health issues we are in a similar situation, but we place very different expectations on ourselves. We have such sadness or fear in our system that we can barely get out of bed, or we have a difficult time doing things like going to Kroger. The amount of intense emotions in our system makes doing things much harder than it has been in the past. And yet we expect that we “should” be performing and functioning the way we did before having all these emotions (and their effects on our body).
There is no way to get back to our previous level of functioning except to take small steps, and take them regularly. The runner would have to walk a little bit each day, a little longer each day. Maybe start jogging at some point, little by little increasing speed and distance until, one day, they were back where they started. We can do the same thing with our mental health issues. In fact, there is no other way to do it.