Health Insurance: how to get it if you retire early?

My husband has Type I with complications. He has amazing health insurance through work now, but we want to retire early at age 55 (he's 25 now). It's unlikely the way he's going now that he'll live to be 70 (I sincerely hope I'm wrong, but we both know the realities of his situation...). I hate to be so horribly morbid, and I apologize if this comes off as too negative. Medicare does not kick in until 65, and his work won't allow us to keep his insurance once he retires. I can't see him being accepted under any private insurance plan, and even if he is accepted, we won't be able to afford thousands of dollars a month in premiums. What do we do? We have been saving up and putting the max into our 401k and 403b so we can retire early, buy a little cottage on the beach, travel a little, and never have to work again. I don't want one of us to have to take some menial job just to get health insurance in retirement. I feel so hopeless...this was a dream of ours and now I feel it slipping away. Are there any other options I'm not thinking of? Should I just forget it and work til 65? 

Damn, I hope they cure this stupid disease soon...