Hey BUJNOWSKI,
It sounds like you're having connection issues, possibly even packet loss, so first I'd suggest hard resetting your modem and router by unplugging them for 5 minutes. If it's packet loss you're getting and it doesn't go away, you may need to contact your ISP for help.
Please follow the steps (if there are any you haven't completed) on the Connection Troubleshooting Guide to make sure your connection is set up properly.
If those steps don't help, you can view your connection by running a traceroute, and sharing the results might show us where it's going wrong. I suggest downloading the WinMTR Network Diagnostic Tool, then use that to run a traceroute to the following IP's (allow this to run for 5-15 minutes);
104.160.131.1
Export the results to a text file and paste them here.
-DTN