Worked out what happened. Last night I logged in to my cpanel just to see that my website nearly reached disk space allowed which was 200MB my normal wordpress install takes only 17.8MB, but 197.8MB was taken!!!
I have in wp-admin folder I found 4 or 5 files called something starting on “c” like cXXXXXXX13446283462834628462893 and they were 33MB each and the last one was only as big as it could fit in remaining hosting space. What probably happened plugin cased something to dump that amount of data in wp-admin folder and that’s why account was showing 404.
Maybe someone here would know what I’m talking about.