I think a support group is a really excellent suggestion - and a partners' one for my wife, too, might be very useful. Right now, she feels as though she's preparing for bereavement: an absolute loss of the man she loves.
As for dressing, my feeling is that it frustrates me, more than relaxes me. When I wear a dress it feels completely natural, but it also reminds me of all the ways in which I'm not (yet) female. That said, I think the compromise towards which we may be moving - for the sake of our teenage son - is to start what you might call transition-by-stealth ... in other words doing as much as conceivably possible while still being able to maintain the exterior role and appearance of a man (eg. weight loss, voice-training, beard/body-hair removal, hair transplant, early stages of HRT). Since - as many Susan's girls can surely testify - one can go an awful long way towards full transition under those circumstances, that may make it possible for me to dress in private and feel a lot more womanly when I do it.
Meantime, I think it's time I Googled a few support groups!