Capability for work questionnaire

I was attended two medicals at the end of last year for DLA and PIP which seriously affected my mental health with all the worry. I accepted that we must have these check ups every couple of years to help catch people gaming the system. I was deemed disabled enough to carry on receiving my benefits thank god. Today I received yet another thick form to complete for what looks like yet another medical. This is for cabability of work. This doesn't make sense to me. It was less than a year since I was seen twice and although I lost mobility (which I think was unfare) I was deemed unfit to work. I'm still struggling with terrible anxiety after the forms and medicals at the end of last year. Anyone else had this?