Don't sweat it! Firstly, change your privacy settings on all your instant messaging and any other apps. Then contact your ISP for an IP change. Update your firewall and router. Change the password of your router, and be sure to use complicated passwords that include upper and lower case letters, numbers, and special characters.
Lastly, of course, don't forget to prevent yourself from further IP leaks. Always stay aware, and, if needed, hide your IP!