Was working all day, then suddenly keeps stopping, now wont even log in.

[Sunlounger]

I ran it for the last 20 hours perfect zero problem. Then for the last hour hour it kept stopping just randomly id look over at my monitor and it had logged out it was at the login promt thingy, now it wont even log in. I log in and nothing happens for 5mins then says (Not responding)

 

[Tony]

are you ok now?