Hi and welcome. I'm sorry you're not feeling well.
Definitely, a better diet plus exercise are going to help. You also sound a bit depressed, and exercise should help with mood. But you need to take it slowly. Fitness goes away scary quickly but to get it back takes effort. So don't be upset or surprised or discouraged if it takes a while. Instead of sprinting, try walking for several weeks. Then, as that gets easier, increase the amount of time and/or pick up the pace.
As for food, you're starting off well but it sounds like later in the day it may go to hell a bit. Try having healthy snacks around the house. Carrot sticks, a bowl of appetizing fruit, low fat or nonfat yogurts, dried fruits, that kind of thing. I'm trying to play off what seems to be a sweet tooth.
Not everything will be fixed in one quick shot, but you can work on things and it will probably help you to feel better if you feel you are making an effort. Oh and try to include your spouse on occasion. Walk together, maybe one day/week. Just walk, don't even talk. It will probably be a good thing to spend time together that isn't spent fighting.