Is there away to find out whose using your # and your email account

Someone has my number and email addresses and are using them. Buying things, selling, internationally too. . Isn't there a way to find out who it is.? our technology has come so far we can find phones that are missing we can find out who has it from camera find out who's taking my email accounts and our phone numbers and using them come on now. I need help somebody's going to find me this person