Would he be open to attending a dietitian appointment with you? Having someone else to reinforce the need for your new diet might lessen the uneasiness for you.
Is there a time you could discuss it with him when you aren't tired and hungry.
I hope he gets on board with your diet soon.
When I decided I needed to change my eating habits, my 12-y/o son was worried that I was anorexic. Far from it, but since I was eating such high calorie junk all the time and then switched to fiber/protein/good carbs and keeping a food diary, he took it as a sign of being obsessed with losing weight. Maybe your husband is having similar worries. He might even be worried that you'll become a different person when you're slimmer and healthier.
Good luck Monty.