What does DH do when DD cries at home? Perhaps if he tried/practised some calming techniques at home, he could use them while out and about. What would he think of a sling? Even at 1 they can still enjoy those, our DS loves his ergobaby and feels nice and cuddly with DH. He cries less and is more patient with everything (otherwise, like your DD, he can be a screaming monster noisy baby).
My DH is similar, but not to the point where he won't go out. He'll say, 'oh, everyone's looking', and I'll say, 'Fuck 'em'. Those with kids/who've been parents understand what it's like, those who are young, or fussy buggers can kiss my ass! I really thought I'd be mortified if I couldn't stop DS screaming, so on a bus, but in reality I do what I can to sooth him so at least everyone can see I'm making an effort. I actually surprised myself when DS came along as I really truly do not give a fig!
Perhaps your DH could throw a few phrases, like: kids, eh? oh dear, poor little DD, are your teeth hurting again? Let Daddy kiss it better. Hang on, milk's coming...
That kinds thing, it often gets more sympathetic looks from people and could diffuse the situation.
I'm very sorry he's acting like this. Could you get the support of MIL or B/SIL to kick him up the arse as well? So it's not all on your shoulders?
Good luck 