I'm a gamer to complain, not support to fix, but I'll try anyway.
Have You tried to reinstall games, could be ssd/hdd. Is it instant process kill (poof and You see desktop / game launcher / other app), or freeze (game stops at last view and You stuck to do anything)?
Have You tried to lover game settings, if some other piece of Your pc fails to do the job, not exactly gpu?
Can imagine lots of possible issues, it's like shooting the wind here.