Question Computer started crashing recently after upgrading psu and gpu.

Mar 4, 2019
Hello people a month ago I upgraded my gt710 with Rx 570 8gb oc and switched rampage 600w psu recently my computer started crashing while gaming everything is ok when im surfing in internet or watching a movie or playing low spec games(crusader kings 2 and some text based games) but when i try to play other games(Verdun,Skyrim,Empire total war)after 2 to 15 minutes my screen goes black sometimes other colours like yellow and freezes unless i force close and reopen it not become responsive and im really frustrated because I am a university student who lives in a country that electronic parts are very expensive and spent his 3 year savings on that gpu and psu further ado in my old gt710 i can play total war with no problem.

Here is my specs:
Msi Armor Rx 570 8gb DDR 5 (oc)
İntel Core I5-4570 CPU
Rampage 600W PSU
4gb DDR 3 ram 900mhz? Maybe im not sure.

Things I tried so far:
Updated gpu drivers.(stopped crashing while not gaming)
Checked my hdd found no errors.
Checked my motherboard its competiable with my new gpu.
Fist day when temp reached 72 it still normal today i tried speedfan and set cpu fan speed at 65 it lasted long but crashed again so i monitored temp while a game is open when it reached 68 degree it crashed again.

I am really desperate here guys there is no way that i can get a refund on that parts plus buying these cost me 3 years right now i suspecting most on RAM but sometimes even a game requires 1 gb most still freezes can happen.

Can some expert lend me a hand?