I'm so sorry that you're going through this!
It sounds like he has some serious insecurities. He's afraid other men will notice you, if you lose the weight! Does he think he's helping to motivate you, or is he just doing this to feel superior?
You can absolutely do this! You don't need to let him affect that. First, make sure you're trying to lose the weight for YOURSELF. You'll never be successful if your goal is to try to make him happy. Be your own #1 priority. You're worth it!
Decide which day you are going to dive into this 100%. Have a friend take some "before" photos of you. Keep them in a secure place, away from your husband and write your official starting date on them. That'll be proof for when you *do* make progress and reach your goals.
Next, I would suggest making a list of specific plans for reaching your goal. What can you do each day and week to reach your goal? Have a series of smaller goals along the way.
For example, get an inexpensive pedometer and try to reach a certain number of steps every day. Increase that number after so many days or weeks. Plan to take a walk around your neighborhood for 10 minutes every evening. That will both get you away from the negative environment and help you get started with your weight loss. If you work, take the long route to the restroom from your office. Check with your friends and see if they would be willing to meet you for walks. If you don't want to draw his attention to your extra walking, then do more walking around your house and go out of your way at the grocery store, or walk every aisle. Walk a couple of laps around the parking lot when running errands.
Something else you can do is to change your diet in subtle ways so he won't notice and try to sabotage you. For less fat, substitute ground turkey for beef when cooking, add less salt to your meal. Consume fewer refined carbs and sugar. Eat green veggies in place of potatoes. Then, start substituting some healthier SparkRecipes for the things you normally fix. If you eat a lot of take-out, make sure *you* do the calling and ask for *your* meal to have some healthier substitutions, like leaving off the butter and putting dressings on the side. I know of one brand of condiments and salad dressings that are all calorie free, fat free, sugar free, gluten free, cholesterol free, and carb free; find some of these at your local store, or online, and put them in different bottles to "secretly" save yourself the extra calories and fat. These small changes will make a big difference!
For support, you definitely have all of us! I'm here anytime you need me!