Pj
I'm afraid it is difficult to offer reassurance as there are too many factors that can affect the experience but as to advice, the best that we can give is to be prepared.
The UC reassessment will be a full review of your claim, a new UC50 and possibly another face to face. You need to complete the form as if it is a new claim, you can use the information from your previous UC50 but make sure that your answers are still relevant to your limitations as they are when contacted.
Have a look at our UC & ESA Claim guide for details of the criteria that you need to meet and help on how to explain your problems on the form.
www.benefitsandwork.co.uk/help-for-claimants/esa1 If you have any specific questions then please return to the forum and we will do our best to help.
Gordon