Oh Katie, its got to be hard for both of you. You for having to wait for him to get down to a decent level (which in all honesty could be a couple of years), and him knowing that hes unattractive and unable to do a lot of things others take for granted.
hes lost already a really good amount of weight, have you celebrated that? any mini-goals to try and pump him up about it? If he looses 40lb and all he gets is you moaning about him being overweight he may be inclined to give up.
I think you should perhaps you should stick with him for a while longer if you truely love him, give him the chance. If its only the weight thats a problem then just wait it out and dont go organizing stuff thats going to make both of you uncomfortable (ie going places that require larger seats).
Perhaps spend more time together doing stuff like taking a day hike. It doesnt have to be hard out walking, just take your time. a day hike can burn up to 2000 calories and also mend a lot of bridges (its done wonders for me and the kids getting along i tell you!).
Anyway, in the end its up to you. Dont walk away without knowing for a fact that you did everything in your power to save it. Otherwise you are gonna end up living with regrets.
Today might be a bad day, but tomorrow will be better
