Plutonium

my BO2 zombies doesn't start the maps, it's loading for a long time and then it goes back to the menu and says "disconnected from the server" or something like that, and when it starts it's dropping at fps, I can't even get into friends' servers or those who already they're there.
the specifications of my notebook are:
intel core i3 7020u
intel hd graphics 620
8gb ram
1tb hdd
PS: I used google translator to write this, I'm Brazilian, I hope you understand.