Hi C
Welcome to the forum, you might want to have a look at the following FAQ which explains where everything is
Welcome to Benefits and Work In case you are not aware, your real name appears to be showing in the forum, if you want to change this then follow the instructions in the following FAQ
My full name is showing, how can I stop it?
If you want to submit a diary, you only need to keep one diary. It's the PIP criteria you should be focussing on - not the conditions. So you might put an entry that says "Unable to prepare a meal because of fatigue. Could not remain standing for more than a minute. (chronic fatigue/COVID)"
Do not feel overwhelmed by this and it's not compulsory to do it. I can be helpful in showing what someone's life is like, but not everyone submits one - even if they have multiple conditions.
BIS