pip advice please

Can someone please advise I was awarded PIP in 2015 only the basic rate, and was told it would be until May 2018, I have now been sent for another assessment in two weeks, I have only just won an appeal two weeks ago for my ESA getting 27 points when I was awarded zero points at my assessment, I have severe depression and anxiety, it seems as though the DWP has something in for me at the moment, is this normal because like I said I should have been ok until May 2018, as this has caused me nothing but stress and anxiety it's making me seriously think not to turn up for the assessment, as I can't be doing this all the time, It's making my health worse.

Thank you.