Is it due to the graphics card?

I hope that I will meet one or two experts in the field who can help me with my problem.

I've had problems gaming for about 2 weeks. For example, if I Fortnite start and try to play there's a black screen on my monitor and an extremely loud graphics card. I don't have this problem with games like Minecraft or Gta 5, but they jerk quite a bit and can no longer be played smoothly). I downloaded and used Furmark for test purposes and after 1 sec everything crashed again (monitor black, loud GraKa). Something like that never happened to me in furmark before.

Does anyone know what that could be? Is it the graphics card vlt. Broken or is the problem somewhere else?

Specs:

450 watt Corsair VS Series VS450 Non-Modular
Intel Core i5 6500 4x 3.20GHz So.1151 BOX
ASRock H110M-DGS Intel H110 So.1151 Dual Channel DDR mATX
8GB MSI Radeon RX 480 Gaming X Aktiv PCIe 3.0 x16
8GB Crucial CT8G4DFD8213 DDR4-2133 DIMM CL15 single

The graphics card needs 150 watts, MSI recommends a power supply of 500 watts (PSU).

Would back up my data and reinstall Windows.

This will rule out a software problem.

Have always heard when putting together the PC that 450 watts are more than enough. In addition, it worked wonderfully for 2 years. Why should it be the power supply now?

In the first instance I would cleanly reinstall the graphics drivers. If that doesn't help, when to reinstall Windows.
Only then can a hardware defect be assumed.

450 watts are sufficient.

Will be as you say.
Was a metal worker and every time it got loud with rotating elements, it was a bearing damage. I would have a look at the fan of the graphics card, if there's any damage, the cooling is not guaranteed, the higher the demand, the more cooling is needed, but no or hardly any cooling if the fan is damaged.