No, even if you could find an "online therapist", I would not recommend using this service. It is legal for anyone to call themselves a "counselor" or "therapist", but in order to call yourself a "social worker", "case worker", "psychologist", "psychiatrist", etc, you must have multiple university/college degrees. Anyone who claims they are a therapist online can technically be any person, and since it is online you don't know who you're dealing with.
Online support groups were mentioned, but if you've done something that you don't feel comfortable sharing with many others or that is specific to you, those may not be of much help.
If you are in school, you can go to your school's counselling services and talk to them, or if you are in Canada you can go talk to some therapists free of charge (under certain circumstances).
But I would recommend trying to talk to a close friend or family member first, to save the extra trouble.