ESA renewal

I am hoping that someone may be able to help me as I am at the end of my tether. I have been in receipt of ESA (previously Incapacity benefit ) (in support group ) and recently (November 2016) had a home face to face assessment for PIP at home and awarded highest mobility component and middle care rate. I filled in a recent ESA form & supplied extensive medical evidence with this form . I have RA & Osteoarthritis as well as other health issues and have today been called to attend a medical. I feel that the evidence I have submitted cannot possibly have been taken into account and stress this places on me and family over and over again is intolerable. My question is , which agencies can I turn to locally to get support? I feel this will be long and stressful process . Thanks for any advice anyone can give me.

Thank you , Gordon. I will contact my local welfare rights as I have a feeling this will be a long and exhausting process. I have been through this situation a few times before and always had to challenge DWP decisions. The process is so stressful and relentless. Previously after waiting for a medical assessment for several months, they called me the night before to say I didn't need to attend! I am grateful for any advice and will continue to use the guides on the website.thanks.