Gradual exposure to what initiates dysfunctional behavioral patterns has proven a very efficient way of management.
The exercise bellow will help you combat perfectionism.
Make a list of situations that usually lead you to aim for perfectionism. Then, attempt to deliberately make a particular mistake in order to confront yourself for not being perfect. This exercise will help you get accustomed to a less perfect version of yourself.
If it seems too hard to do, picking for the mistake that won't particularly upset you and gradually progress two tasks that you find difficult to accept imperfect results.
Such tasks may include
Wearing a shirt that wasn't properly ironed
Sending a friendly message that includes a spelling mistake
Being a bit late on an appointment that isn't urgent
Proofread an email no more than once
Limit the time you spend preparing a presentation (e.g. 2h/day).