Constant disconnections

I am being dced constantly since the start of the league, do not know why. It happened when I was afk/trading in my hideout, when I run a map, when I use a portal or in transition to a map. When it happens, my ping spikes from normal towards 18-20k (on performance graphics window, my ping is normal and everything works normally), then I get booted back to main menu with "An unexpected disconnection has occured."

Specs:
NVIDIA GeForce GTX 1050 Ti
IntelCore i5-4460 3.20GHz
16gb RAM

My Game settings:
DirectX12 (Tried Vulkan and DirectX11, crashed on both too)
VSync Off
Triple-Buffering Disabled
Engine Multithreading On
Every other graphic option is set to lowest