Everyone has bad days. I have had days where I felt so bad I stopped doing all my habits that day. I just made sure not to do that two times in a row so I could avoid making a habit out of doing that. When you have a difficult day don’t just decide your bad at something when you just had one difficult day. I have had bad days where I thought I couldn’t do something. The key to overcoming that is consistent actions towards whatever you want to do, so you eventually get good at it.