why internet is so jumpy when playing games?

Your ISP is restricting your bandwidth when you use too much of it. 'ISP throttling'. I use a vpn to prevent that. You can check it out if you like, its called 'purevpn'. Basically if youre activities are encrypted, your ISP cant tell how much youre using, therefore cant restrict it. Hope that makes sense

How about doing something productive with your time instead of playing games?!

Playing games require both high-performance computer and good internet.