El capitain problem

Please, I really need help and a response quickly because now I cannot open my own session only the guest session ! I need to use my files and ohers...

The problem is I downloded the El Capitain yesterday morning and when I want to use my Mac on the evening, I couldn't open no more my session ( the computer switch on and I can choose between my session and the guest one). When my session sarts to download a error message appears and the Mac turn off. So I read that I'm not the only one with this problem and it's seems that there are other problem of battery when El Capitain is downloaded !

So I'm not sure (or pretty sure), that El Capitain is not really ready to be download and gives too many problems.

I think Apple should stop that version because of many problems which appear.