MG I don't mind you asking at all, though I'm afraid you might not like the answer, which is I divorced him. He did take it badly initially and I did worry terribly about him and feel awful guilt. But it was without doubt the absolute best thing to do for both of us and if you asked him now I'm sure he'd say the same thing (he is now happily married to someone else).
In my case it was made easier because of our extremely precarious finances. I was the only one with a steady, full-time job, whereas he drifted from one part-time job to another, sometimes with no income at all, occasionally interspersed with self-employed business ideas that always folded and resulted in debts that I had to pay off as I was the only one earning enough to do so. The final straw came when he came up with a 'wonderful business idea' that he wanted to finance with a loan using our house as security.
If I was to describe my XH I'd say he's one of life's dreamers. In another world, with the right set of circumstances, one of his dreams probably could make his fortune. The world needs dreamers - their off-the-wall ideas are sometimes the ones that turn out to be the iphones of the future, etc. The trouble is, it's bloody hard living with these people as they tend to leave the ordinary mundane things (like buying food and earning enough money to pay the mortgage and gas bill) to their partners. It's ok for a while but it is selfish to expect anyone to do this long-term.
I say all this as if my XH was some kind of creative innovator, whereas the truth was that he lacked the ambition and drive to succeed in any conventional field so was trying his luck at one of his own making. He would never come up with anything spontaneous for us to do as a recreational activity, and left to his own devices would spend all weekend reading/watching TV/playing computer games, though would always happily do whatever I wanted him to do if I asked. He wasn't a sponging 'cocklodger' type, just a hapless but highly agreeable man who had spent his whole life surrounded by strong women who had looked after him and so didn't know how to take control himself.
I guess that in the end I just got fed up of being more like his mother than his wife. As I couldn't make him change his behaviour without fundamentally changing his personality, I recognised that the best thing to do was for us to call time on our marriage. I couldn't face the thought that if something happened to me (e.g. a long-term illness), our whole lives would fall apart because he was incapable of handling it all for even the shortest period of time.
Like I say, it was difficult, but after the initial hurt and anger on his part we divorced reasonably amicably and parted on good terms. People who lack the energy to take control of their life are rarely capable of sustaining anger either, which is at least one silver lining to this particular cloud. I'd say your DH will probably react in much the same way.
Sorry for the essay. 