hello again, if you overclock your gpu it would cause more "bottleneck".
and yes your powersupply is not great at all and its powering a pretty high end setup it , this is dangerous since you are risking your components with such a low quality psu
id suggest you get.
corsair TX/RMx/HX and if you can afford AX series or go with Seasonic Focus plus gold or if you can afford go for their prime models.
id recommend you not to use your pc that much for now. also now that i think of it it could be just a cpu bottleneck for 1080p 60hz since the 2060 is pretty powerful and more than enough for 1080p gaming. id suggest maybe cranking the details to the max and if theres an upscaling option like resolution scale or what not you can increase it to 150% to mimic something like a 1440p experience.