A Hacker has my IP... what should I do?

Basically, I have a static IP. Someone has it, and they can see/control my computer, and they have my keystrokes down on a log. I didn't accept any files from them, but aparently they can type my IP into their Address Bar and byp the username/pword thing. I may have stopped them, but I'm not sure if I have or haven't. What should I do? (start off with easier ways please)