(First, Val, congrats on trying Al-Anon...HUGE step for you).
On your question, I don't know I have an answer. Being anyone's trash can isn't fair, having been one myself. Had a sponsor tell me ages ago that fertilizer doesn't do any good unless you spread it around...meaning, I try not to lay all my sh*t on one person. Sounds like your husband isn't there yet.
I can't answer for your husband. I can tell you my feelings in a similar situation. When I'm in that mood, I tend to be hypersensitive. What works for me is gentle honesty because I'm sensitive to rejection. It's not the same as babying. I'd rather someone tell me calmly, but lovingly, that hearing all this awful stuff is sometimes too much for them. I'd like to hear that they're only human, too, but that they can manage bits. Umm...at the same time, it's up to me to realize and accept that people are just people.
That's one hell of a tall order as far as my preferences. And results aren't even guaranteed!
OTOH - I probably sound like a damn cheerleader - there are likely Al-Alon meetings at all times of the day for you. (In my worst moments I'd sometimes hit a couple a day to keep my sanity and it got me out of the house). And, if you hear someone in the meeting with whose story you seem to connect, ask 'em for their phone number, get a cup of coffee, etc.