Hey Toad,
You can do this! When I started, I found several cookbooks at the library of vegan/vegetarian cuisines. Most notably, Indian food. That stuff is NOT bland. There's plenty of Mexican recipes as well that are compatible, and it's pretty easy to McDougallize any recipe. Just omit the oils and animal products.
There are some absolutely wonderful recipes here on this site, but I also recommend the
Engine 2 cookbook. Rip Esselstyne is a firefighter who noticed that the vast majority of their calls weren't for fires, they were for strokes, heart attacks, and other calamities brought on by lifestyle choices. He created a cookbook that is kind of transitional. There are ZERO added fats, but he does have some nut based sauces, etc that might possibly make it easier to move from the SAD that you're trapped in, to the healthy foods we enjoy in the whole foods, plant based world. That cookbook is in the library, too.
In the Starch Solution, I found Thai Curried Rice to be my favorite recipe. Also love Mushroom Barley Soup. Easy to make big batches, VERY flavorful and luscious, satisfying. If you make a big batch of a recipe that you love to eat, then when that urge strikes to drive down to the C-store for junk, you can just heat up a serving of it. Or, if you don't have anything made, a bowl of oatmeal is a yummy evening snack. With frozen berries? Oh yah!
Stick around. You're right about lifelong obesity taking its toll on the old joints as you age. I am testimony to that fact, because that is my story too and I'm coming BACK after straying
Make this forum your go-to and keep writing here. Follow the plan. Seriously, it doesn't get better if you stay fat AFTER middle age