Here is what it looks like to me. (Keep in mind that I am a recovering alcoholic with 25 years of drinking behind me. I have A LOT of experience with other alcoholics. I'm not judging the behavior patterns of alcoholics as bad or good - I'm just really clear on the fact that alcoholics use whatever conscious or subconscious tricks and games they have in order to avoid facing their alcoholism. Even if this means hurting people they love.)
You appear to be looking at this with a very open mind in terms of where your bias could be, how it could be manifesting, what you might be miscommunicating or misunderstanding. You seem to want to take responsibility for your own role and to expect that your bf will do the same because you know him as a fair and good person. You appear to place a very high importance on being fair.
Your bf appears to be taking advantage of that open mindedness of yours. He doesn't seem to place much priority on giving you any benefit of the doubt like you do for him. He seems to be primarily protecting his position and attempting to turn things so that you are responsible for his feelings, and his actions. He appears to have an interest in deflecting blame, avoiding responsibility for his words and actions, and finding a way to encourage you to question your own thoughts and feelings as invalid.
Everything about his actions that you have told us here smacks resoundingly of the actions of an alcoholic in deep denial and looking to avoid facing the truth about himself. And nothing, absolutely nothing, you say or do at this point will be able to help him. He has to help himself and you have to help yourself. He may or may not see the truth and seek help. But don't think that you have the power to illuminate his problem for him. He will not be able to see it. He will turn it around again and again to challenge your perceptions rather than admit his problem.
What you have the power to do at this point is to protect yourself.
I am sorry that you are having to face this mess. It's not your fault and you're wise to be questioning his behavior and your ability to accept it. If I were you, I would make the assumption that his behavior of denial, blame, and dishonest avoidance is due to alcoholism and that he has shown himself unwilling or unable to address that at this time or in the near future. And I would look immediately for ways in which to extricate myself. I wouldn't even engage or let him draw me back into a discussion over the issue. Any discussion will result in him twisting things and blaming you or apologing profusely and then not following through on promises.
I'm sorry. That's just what it looks like to me. I feel for you.