My hotmail account, everytime i go to write an e mail its in blue writing and underlined and when the receipan?

when the person clicks on it it is a chinese clothes web site, how do i get rid of it ? also i see my contacts list which only ha s2 people in it now has over 100, i am apparently sending e mails at 3am etc and my in box has about 50 e mails a day from ceramic bead sellers and lots of delivery unable to sends? what has happened and how do i stop? im in the uk