His anger is coming out at you. However he is not angry with you. He is angry with himself. I believe that there is no OW and that he is deep withing withdrawal stage. Everything is going normal, for MLC. He must go backwards into his tunnel to think and decide what he wants to do. This is one of the hardest times for the LBS because you think that you are on the way to reconciling but the MLC'er pulls back and all seems lost. Let me assure you that it is not. You must continue to give him space. Live your life as if he is not coming back. But you can have hope that he will.
You must not pressure him. All will be revealed at the proper time.
Have you read the reconnection threads and the withdrawal stage of MLC? It might help to go back and re-read some of that stuff as a refresher course. The crisis is not yet over but it is different.
Reassure your son that everything will be fine, I know the darkest time of the storm is the worst but it too will pass.