Why does my valorant keeps lagging?

And it doesn't even tries to use my CPU, sometimes the vanguard runs consuming over 50% of my CPU but valorant doesn't uses the CPU, GPU. Normally it shows 60 fps but when i have clutch situations, fighting conditions the fps automatically directly drops to 5-10 and game screen totally stucks! i checked my taskbar to see the stats there is everything well working under CPU 50%, Memory 80, Disk 5-10% and well GPU over 50