My understanding of forgiveness is sometimes it is more of us than it is for them. If the situation doesn't allow you to tell him f2f then maybe in a letter or poem or journal that you can keep, bury at a special place or burn sending the words to your HP to deliver to your A's heart at a time when he's ready.
Sounds like your HP is taking you thru an awesome path of healing.
Be especially kind to yourself as you walk this road.
Progress Not Perfection,
Rita