Someone made a facebook account with my yahoo?

So throughout the night I got emails on yahoo saying that someone sent you a friend request and i need to confirm my account etc. I first got an email saying that I need to confirm my account and then 5 minutes later I got an email saying welcome to facebook and I never even confirmed the request and then later on I got emails saying people have sent me friend requests and saying people confirmed me as friends, I then got an email saying that I have requested anew password or I have forgotten my password and then 5 minutes later people sent me more friend requests and saying I confirmed friends. I have no idea what's going on not many people have my yahoo e mail address. I really didn't want to delete my yahoo so I just changed the password. The person even used my name to make it please help me and please advise me on what I should do