I just downloaded the game from GOG and launched the game but it freezes everytime i go full screen. One solution online told me to disable vsync and launcher but the problem still persists

That is a wrong solution...

For now you have to disable fullscreen optimizations feature from properties of .exe file, that will cause a blur to some objects and character models, or use borderless mode, but i think that will cause stuttering... (and stuttering will gone only without fullscreen optimizations feature)

also, i recommend to disable game mode feature to fix a bug with alt-tab that cause a 10 secs. of black screen

What worked for me was to install DXVK. It translates DX11 to Vulkan and with this I am able to play in full screen with no issues. Depending on your PC you might get a performance boost as well.

https://github.com/doitsujin/dxvk/releases

Just download the latest release and drag and drop the files to the game installation folder.