I know how you feel with regards to difficulty getting started. I've started and stopped so many times I lost count. I think the first thing you have to do is approach this as a lifestyle change and not think of how you are depriving yourself. Any activity is better than nothing. If you can walk in intervals, do it. Try to push yourself a little farther each time. I'm no Doctor but walking is better for the back than sitting. If you haven't consulted a doctor about your weight loss troubles do it. I found out I had some endocrine issues making weight loss difficult. I find that low carb diets work best for me. I have had the most success with this and I feel better and am less hungry. I avoid all bread, sugar, pasta, rice, potatoes, baked goods. If you don't like salads try vegetables other ways. I love roasted vegetables with a little olive oil, balsamic and seasoning. I eat a lot of eggs, meat, nuts, cheese in moderation and find it easy to stay under my calorie limit. I have one cheat day a week but not all day. I'll have some carbs or that's when I have a few or more drinks. Good luck man.

I have a chronic illness that makes sticking to workouts a challenge, and I have a tendency to over snack when I am distracted or upset or in pain. So in this respect I am in a similar situation.

I try to keep myself distracted, If I am playing video games, doing things with my hands I can't snack. Likewise time spent reading or meditating also lowers stress and keeps me from snacking.