Power supply is good, don't worry about that, a lot of people think that shutting down and restarts are PSU problem but mostly they are not.
Game have problem with certain confiigurations.
Did you tried disabling Origin overlay or go offline? Eventually you could try program called Outcome
Check energy saving settings and turn off everything you can.
Just to be sure you can download http://www.mersenne.org/download/ and run It for 30 min to check if CPU is ok, at certain situations It may be your CPU cooler and overheated CPU shuts down your PC instead of boom🙂
do same test with graphic card and if everything is ok there is no way that anything with your build is wrong, expecially if you can play other games without issues.