...yes, I have really bad mood swings on my HRT : s
I have been on HRT since I was 18, for premature menopause (not cancer related), and I get really moody when I'm taking the progesterone (I take separate tablets for the oestrogen and progesterone, as this was the best regimen for me.) I've found that taking 2 evening primrose tablets morning and evening stablises my mood and makes me less emotional.
There are many different styles of hrt, to encourage your husband to ask his doctor for different type if this one is making him overly moody. He will feel more content and relaxed once he finds one that really suits him (as long as it also fulfills his medical requirements, of course)
hugs and good luck to you both, love Emily