oh boy!
Guys I tell you something what will change your life , when you using internet based on an router who split your connection speed to multiple devices connected throught LAN /Wi-Fi your connection speeds get splited , less conection speed for an device in terms land into high ms , and that high ms is duo to the package changed between your computer and the game server .
Secondly you may be on wi-fi connection and that's why you have high ms .
Lastly if none of these worked , try to watch your routing settings and change wi-fi password , maybe someone else acces our router and use your internet creating you problems.
So basicaly based on how good your internet is maybe he can't handle to offer you best speed , when someone acces wi-fi and may load stuffs like videos or download apps or download something else on another computer could creat lag , sames apply if you have smart tv and go youtube and apps like this , same apply and when people watch online movies or channels etc...
There is a trick new routers have , if you go into settings based on credentials from contracts with your internet provider you can log into settings and limit the amount of speed for every device , however i am not sure every router can do this , and that's depend from model to model...