If you still love each other, have you ever discussed an open relationship? That is if he still wants sex. He probably doesn't want you to feel this way either and doesn't know how to help you. It could be the change, it could be many small contributing factors that make him less sexually desirable to you. To be honest, I'm not sure how many couples are having very regular sex that isn't partly a chore. That may seem like a harsh thing to say, but emotions have a huge impact on how physical you want to be with your partner, both ways. You sound as though you are living your lives in each other's company all the time, with no breaks and no independent hobbies or even friends maybe, outside the home. Do you?
This will slowly but surely eat away at most relationships as they become monotonous and predictable. Can you not find a hobby or friendship group close by? MeetUp is great for finding new things to do in your local area with new people. You need to get out, and try and do things you've never done. Go for a walk daily, see if any neighbours need help or a dog walk, just to get out and do something. Encourage him to do this too. What are your interests, what are his?
Perhaps sit down with him and make a plan to try one new thing outdoors, or at least outside the house. Just one thing. If you enjoy it, schedule it in for once a week and then maybe twice a week if you really find it benefits you both.
Don't feel bad for not wanting to be intimate under these circumstances. It happens to more people than you realise, but you are brave enough to ask for opinions.
Does your husband still make you feel loved, or does he only give you attention when he wants intimacy? Is your husband overweight, in good health, has bad breath, etc etc etc? Does he take care of himself? Do you take care of yourself? If you feel you may have let that ball drop, why not make a plan for self-care, both of you. Do small things that make you feel good. A manicure, facial, skin brushing, improve your way of eating, try fasting, go for a very brisk walk every day or twice a day, even if it's just for 10 minutes. It will make you feel better.
Sorry for waffling but I hope it helped a little bit. Sex is not the be-all and end-all. It doesn't have to be.
My motto is 'do one thing every day that makes you happy.' Happiness releases serotonin/dopamine/endorphin fix. This can work wonders.