WCA - submitting medical evidence to Atos

I have CFS/ME and depression. I first claimed ESA in 2010, was passed as fit for work following a WCA but went on to win my appeal on exceptional circumstances (suicidal ideation which was ignored by Atos and DWP).

I was sent a ESA50 in May 2013 which I returned with medical evidence from my GP, counsellor, NHS ME clinic and Mum. I got nothing back - no letter, no WCA appt.

Since then, my Mum's health has declined and as I live with her, this has at times put me under considerable pressure. I have not had to dress or wash her but she needs a lot more emotional and other support as she gets older.

Now I have just received a letter from Atos asking me to attend a WCA later this month.

1. Is this unusual considering the time lapse between the ESA50 and the WCA? Should I check with the DWP that the form hasn't been lost in the post?

2. Should I attempt to gather any medical evidence and take it into the WCA? Would the Atos official take it or insist I send it onto the DWP? I'm trying to off-set the likelihood of a mandatory reconsideration period if I'm put in the WRAG or passed as fit for work.

Many thanks