You can't make anyone understand. He has to accept that you would have a problem first. Then as his acceptance grows, he will continue to learn about it until he reaches a more full acceptance. There may be an ED support group for spouses that he could attend. Or you could contact them for help and resources. Find out what he knows of the problem and help him grow in learning his supportive role--VERY IMPORTANT. You need his support in order to succeed. His frustration is likely only holding you back some. Changing our habits is MUCH more than just "eating right" or going to a gym. There is a lot more involved with behaviors.