Am I making a huge mistake by making excuses for him?

Just how many red flags does he have to wave in your face???? Get rid of him and move on with your life. You have enough problem of your own with out taking on EXTRA baggage. With what he had done to his self you should not worrie about him in the least. He will not take responsibility for his own actions so why should you worrie about it. I hope this has been of some help to you. Good Luck. You deserve better.