you are allowed to have bad days.
We need to give ourselves permission to have bad days. We cannot expect to be all good all the time. It's not natural. Some of us do have more bad days than others, but it's the same either way. We are allowed to have bad days.
If you are in the same spot as me, struggling with a mental illness, and trying to do better. You have to remember you are allowed to have bad days. I remember when every day was a bad day. When I was unable to remember the last good day. I have come so far since then. It is of the utmost importance for me, you, us, to keep the mindset that a few bad days is not evidence of 'getting bad again'. It's the evidence of being human. It's the evidence of fluctuating emotion, mood and circumstance.
You must do what you can to not let a bad day or a few bad days hinder your recovery. You must do what you can to not let these fleeting feelings bring you back a step.
I know there can be exceptions to this train of thought, there almost always is, but even then my main point still stands true. You are allowed to have bad days.
Do what you can.