If someone else used your deductions when your filing status was SINGLE, you should file the IRS fraud form -Form 3949-A Information Referral.
Use 1040-X to revise or correct information on an already submitted tax return.
Mention For 3949-A if you filed or will file that.
Review your corrections carefully and be sure it is all correct before mailing.
You can amend two years back. the deadline for the third year back has passed.