I hope mark was too drunk to know what was going on.
Hindsight can be tormenting, but think of those people who do not have the insight to look back and see their faults. We can't change the past, but hopefully we can learn from it.
Sometimes in a situation where the person that you wish to speak with is no longer here it can help to write them a letter. a letter apologising, explaining. In a way it's a letter to ourselves too, as it helps release our feelings, that's like what you've done now. shared your pain with others, hope it's lightening.
so sad, thanks for sharing