I’ve dealt with the same issue for a number of years, also with an administration member of my HS. I have tried a number of times to forgive but it is hard and fellings of anger keep coming back. (I made decisions in the past based on their actions and the results of those decisions still affect me, reminding me of the past.) I’ve been able to suppress these feeling by blocking out my entire HS experience. I never talk about my years in HS and even refuse to answer when asked what HS I attended.