Pc keeps crashing after upgrades

Hi, so I decided to upgrade my pc a some time ago and all my parts finally arrived today so I got to replacing my cpu from an AMD 3 3200G to a 9 5900X with a new cpu cooler, my gpu from a gtx 1650 to an rtx 3060 and replacing my psu to one with 550w (used to be 450).

It's probably worth noting that while I'm not exactly a pro in pc building I have built a lc before and everything was quite simple. The only thing that went wrong was that I somehow can't find the cable for the sys_fan on the motherboard after being sure of having unllugged it while getting out the old psu, but when I plugged in the new psu and tried it out everything seemed fine so I just went on.

So first I replace the psu and everything seems to work, then the gpu, everything still seems to work. Finally I replace the cpu and everything still works (I think it might be noteworthy to mention I didn't stress test anything after installing the new parts individually, I just checked if they were being registered and if the pc worked generally).

I notice that wallpaper engine seems to be frozen so I open it and try to fix it. I accidentally close it and immediately when I reopen it, I get a blue screen. My pc restarts a couple of times, crashing each time before I get to my desktop so I decide to check some part individually.

I remove the gpu and plug in my monitor directly to the motherboard (which I think should work but I'm not entirely sure), but the monitor says that there's no signal. I try another monitor and DVI instead of HDMI and so forth but no signal. I notice the vga light on the motherboard is on and I assume it's because there's no gpu but I'm not sure about that now.

Then I try to use my old gpu to at least get to the desktop without the new one since the monitors aren't working with the motherboard. Still no monitor works and the vga light is still on.

Out of desperation I try it with my new gpu. Vga light is off and everything seems to be working like before it crashed. I try to see if putting it under stress will cause it to crash again and boot up Cyberpunk.

Everything seems to be working fine except that the gpu usage seems very low (like 5% in total and only like 0.5% from cp77). Then I get extreme frame drops so I try to fix that and for 15 minutes or so the pc works completely fine. Until I close cyberpunk to restart my pc and I get another blue screen. It restarts and crashes again almost immediately.

For additional information: I have some corsair 2x8gb of ram and my motherboard is an msi b450m pro-m2 max. The new cpu cooler is a pure rock 2.

I relly don't know what this could be. I remember hearing that random or seemingly random crashes might be from a weak psu but I'm pretty sure that 550w should be enough for a build like this.