Totally agree tell them your worst day
If things have got worse since you made the claim i would send all your evidence in before the home visit
i was told you could give any additional information to the person doing the assessment , it turned out to be incorrect the guy who did my assessment would not take anything from me has he said he worked from home and was not allowed to take anything from me due to data protection so i strongly advise sending it in before hand and sending it recorded delivery
Th e main things to remember are 'safely , repeatedley, to a acceptable standard and in a reasonable amount of time ' if you cant do something safely repeatedly to a acceptable standard and in a reasonable amount of time then you should be assessed as not being able to do it
eg if you have tremors could you safely lift pans with boiling liquids in them ?
if you were to go out how far can you walk before ypu experience discomfort pain , if you did it once could you go out to the shops a second time if you needed to , if the answer is no then you would not be able to it repeatedly
Hope this helps