My server is lagging / not recognizing clicks quick enough. Help.

This is either your network is not strong enough to connect to the RDP (likely) and is hopping or the CPU is overloaded. Check two things:

Your local connection may be hopping. Give it some time. If issue persists, please check CPU of server. Check CPU/RAM of Server: It’s usually CPU overload. Try this:
Open Task Manager
End any programs hogging the CPU
Restart the server if needed to close out all applications