Hi N.,
Wow, I am so sorry for the loss of your son. I agree, as a non-professional, it sounds like your husband is depressed over the loss and does not know how to cope. My husband also lost a son about 12 years ago, and also had a very hard time...esp. since there was no one to "blame" (cancer). I don't think men are granted the same opportunities to deal with emotional pain as women are (in our culture), and so sometimes they end up being complete jerks to those they care about most as they do not have any other outlet for the anger, sadness and frustration they feel.
Anyway, so where does this leave you? -- You can't keep going on this way as it is not healthy for you or your surviving child(ren).
If you haven't already, try, try, try to get your husband to a therapist/counselor/etc as it sounds like he needs some help. We all do, sometimes afterall. As the song says, "we all need someone we can lean on...". Anyway you can get him to go is acceptable, including couples counseling, which you might benefit from as well! Once in front of a qualified professional, they can recommend if you/him would benefit by addl. individual, grief, or couples counseling, etc.
Good luck. Sorry this is so long (I had intended on it being a short response!). My heart is with you.
A.