As you have changed your password then go to this link:
https://skyid.sky.com/authorise/manage
If you tick "Sky Apps" and then the remove button, then anyone using SkyGo or SkyNews or SkySports apps etc. using your credentials will have the previous auth token removed and will be forced to sign in again (using the new password only you know). Will mean people you want to use your ID will need to do the same, but will force whoever is using your previous details off!