Xfinity Extremely High Latency in Crystal Lake IL

Hey all. I'm a new customer of Xfinity and purchased Internet from their store in Crystal Lake IL. I'm APPALLED by the high latency of the Wireless signal to my laptop which is in line of sight of the Xfinity Router. I worked in a very rural part of the Republic of Ireland for Years! There, I used THREE IRELAND and had very low latency despite the fact that the area would be hit by large gales, wind and snow. In Ireland, every now and then I'd have a High Latency problem which prevented me from working Globally with clients across the world. I bought a signal BOOSTER and Repeater and had a number of these small boxes scattered across my home. Can you recommend a way of increasing the signal strength? My understanding is that the Internet cables are Buried Underground which reduces the signal strength to the Xfinity Router.

Tom