<<< Does this mean 2200mbps and if so why is my connection speed only 100mbps? >>>
No, it doesn't mean 2200Mbps, it means 2.2Mbps - 2200kbps (kilobits per sec) or about 275kBps (kiloBytes per sec). Your network connection between the computer and the router, at 100Mbps, is running approximately 45 times faster than your broadband internet connection, so I don't think it is having a serious effect on your online gaming! :-)
Obviously, if you connect a 1Gbps (1000Mbps) adapter to a 100Mbps port, the speed of the connection is going to be restricted by the slower port. If you have a need to run your Local Area Network at 1Gbps between your computers, you could install a Gigabit network switch and connect the computers and router to that. The computers could then communicate at 1Gbps while connecting to the router at 100Mbps for internet access.