i agree with sannah. if this is the first time you're thinking of trying to help him, do it. don't stop after the first time. do it often, and as you know your dad better, try every way of tackling the problem (i.e., try being nice and kind a few times; if that doesn't work, then try the hard approach--but don't give up). obviously, your dad needs more help than ever right about now. and like sannah said, he won't do it by himself, but
he might do it if you get him to a place, or if you arrange for a counselor for him.
my sister and i have tried to get our mother to recognize some issues that she's been having, and that have impacted the rest of the family for at least 6-7 years (not drinking, or drugs, or anything similar, but nevertheless, something that was and still is destroying her own life), and we've tried all kinds of approaches. she just couldn't be moved. wouldn't listen. however, you dad may be more open, more vulnerable right not, and he may really need and want the help, but not know how to go about getting it.
the fact he's taking to drinking more because of his wife's death a year ago complicates matters further--you know he's still grieving. he really NEEDS help!!!!! you're a wonderful daughter for looking out for you dad, and for asking for advice. maybe you and your husband can form an ally of sorts, and together get him the help he deserves. since you're on crutches and all, i believe you can do some or most of this through the phone.
see, people turn to drinking, doing drugs, gambling, etc. because of deep underlying problems (like you've mentioned)--it's the easiest way to numb oneself. i really don't blame them. some people don't know any better. that's why those who do (know better, that is), may have it it in their hearts to steer them in the right direction.
i wish you all the luck and many blessings!!!