[FPS DROP] Mojave Macbook Air 2018

Hi guys, I was playing on an old Macbook Pro 2010 with 8gb of ram and an SSD, league was ok. Not a lot of fps, but at least i could play some TFT in the free time. I was using High Sierra. Recently I've upgraded to a Macbook Air 2018 but the FPS are dropping massively It starts with over 60 fps but then, every second, it freezes up to 0. How can I solve this problem? Oh right, i forgot to say that YES i have a Windows PC that I use for gaming but when im on the bed i want to use my Macbook

Right now i'm using Mojave 10.14.6