Something else to consider is trying to reduce overall inflammation in the body through diet. It won't magically cure your mobility issues BUT can help your body heal itself faster by greatly reducing overall inflammation leading to reduced pressure and pain in those problem spots.
I read a book called the Hormone Diet by Dr, Natasha Turner who is a Naturopathic Doctor. In this book, she advocates a whole food diet, low in carbs with emphasis on good fats and quality proteins, and veggies and talks about the need to detox from inflammatory foods and balance your hormones after which weight loss will come easier. A few of the foods she stresses causes inflammation are : refined sugars grains (in particular gluten), too much Omega 6, too much saturated fat, bad vegetable fat/omega 6 overingestion, and processed foods.
Now I haven't followed her ideas to the tee but they were quite interesting from JUST an inflammatory perspective. I don't typically take a lot of stock in what medical "professionals" say or write about - most especially those claiming to be health or weight loss experts, but something struck me in the inflammation references she makes.
I know myself that gluten/wheat is THE MOST inflammatory thing I can ingest (from my own experimentation). THere was a time I was over 320 lbs, could barely walk, I woke up every morning in pain (back, hip, neck), I had to sit frequently from fatigue, I had plantar fasciitis in both feet, and god help me if I needed to support my weight by kneeling or using my arms. No way. And I took a lot of OTC inflammatories - they didn't help much yet I shunned asking for MORE pills to help with the pain.
After I quit wheat (but didn't go low carb) - a few things happened. First off, within a week, the aches all over my body started subsiding. Soon, my feet were better. Then my knees bent easier, my back acted up less, the swelling in my feet went away, in short, everything got better (not 100%) and moved freer than before. My energy went up. In short a vast improvement within a few months. I don't think my joints etc will EVER be the same but I think that they feel the best they have in years.
Bear in mind I did all this but didn't have injuries . Pain was constant though.
Other signs of inflammation from wheat - acne and dermatitis on my scalp. Those also cleared up. My skin -which never responded to special washes or hair that I bought crazy amounts of shampoo for are both clean and blemish/flake free.
Now If I eat wheat (or accidentally ingest) - within 30 minutes, I feel the skin on my face itching and a stabbing pain in my left knee. I also get a dull headache, and feel the fatigue hit like a brick wall. No kidding.
I also found the by product of not eating wheat (even on higher carb) was less hunger. This was supported by reading of wheat belly when it talks about the addictive qualities of modern wheat. I wholly now believe it spikes my appetite and affects my own body's ability to tell when I've had enough.
I understand the struggle with trying to stick to a new plan when especially when you are pain and/or struggling to just get around. Years of food addictions make it harder. I still struggle years later but am able to keep in mostly in check. The progress thing, right?
I would suggest starting reading about anti-inflammation foods and at all costs avoid gluten at the very least even if you can't go full out low carb. If you can avoid grains altogether that's even better - but if you find yourself reaching for starches, try to make them things like potatoes, sweet potatoes, rice, etc. Avoid wheat (and sometimes corn - can have the same affect) - and refined sugars
at all costs.
Although I have not lost a huge amount of weight - the way I feel overall from a pain perspective is incredibly improved. Hope this helps you think about food not just in relation to reduction of weight but in the medicinal sense...good luck on your journey!