I recently married and have found out that at the time of the wedding my wife was almost two months pregnant with another man’s child. I am angry and want an immediate divorce, but I understand that this isn’t possible until I have been married a year.
In your case you can proceed straight away, since you will not be presenting a petition for divorce but for the “nullity of a voidable marriage”. Assuming you succeed it will be as though the marriage never took place. See a solicitor.