Help with internet traffic monitoring!!!

Hi, I live with 5 roommates and they all connect to the wifi using several devices each. As you can imagine, this creates tremendous lag and interruptions when I am trying to use my device. I was wondering if there is any way to set up some sort of QoS or regulating how much bandwidth each device gets while I am trying to game. I will really appreciate help with this as it is extremely frustrating trying to play while lagging or trying to do my assignments while the websites I need do not load. Thank you all for your assistance!