I now how you feel dude. I am in this exact situation. Only difference is I feel like a 'trophy husband'. If I go to gym and train, do yoga, or swim. I get snide remarks on how I don't want to spend time with him. Ironically when I stop training, and lose weight, I get shit on for not looking after myself. When I want to buy healthy food, I get told off for buying 'stuff that tastes like crap'.
Your 'other half' will most definitely have an effect on your progress. It can be good or bad. I had hoped for support from mine, but no such luck. It just fuels my fire at this stage. If I had a supporting partner, I would most probably be much bigger by now though.
My advice to you is this:
Sit down, and talk to him. Explain how you feel and what your goals are. When he want's junk food, order the healthiest option from that restaurant. I don't know ha your financial situation is like, but if you can buy your own healthy food do it. Shop around for inexpensive options. Look into flexible dieting, where you don't have to eat healthy all the time. Download myfitnesspal on your phone and make sure you stay in a caloric SURPLUS daily. Let him/her know you love them, and that you are doing this for them too and not only for yourself. Maybe try to get them to train with you a few times in a week.