Hi Sarah and Welcome to the forum, you might want to have a look at the following FAQ which explain where everything is
Welcome to Benefits and Work Is this the full PIP2 form or the shorter version that asks whether things have changed?
If it is the full from you should fill it in comprehensively, explaining why you cannot do things. Our PIP will help with this.
PIP help for claimants If it is the short form, I see no alternative but to tell the truth. We expect any report of 'change' would trigger another full form, where you can explain your situation (I say 'expect' because this form is new to us and we don't know exactly how it is going to work).
May I suggest that you bookmark/favourite this on your web browser now so that you can find it easily in future? This will allow you to return with further questions or comments about your PIP review without having to start a new topic each time. It helps us enormously when everything relating to the same claim is kept in one topic - and I hope you will find it useful too