Would using otc 1% hydrocortisone on the anus for two months 4 times a day do damage to the skin that is irreversible?what would be the complications?

Unlikely: The anti-inflammatory effect of this mild steroid cream is helpful and well tolerated by the skin. It is often used in this way for extended periods. Higher potency steroids might produce some tissue thinning, but this is not the case with 1%hc. It is hyped as "the strongest otc" steroid, but is actually one of the mildest ones we use.