I can relate. It’s a constant struggle. I was able to lose 35lbs over about 10 months, but not until I realized I needed to want to lose the weight more than I wanted to enjoy the comforts of what my palate dictated. I know that’s not what you want to hear, but as you get older, your window to figure out a solution shrinks before that cascade of health issues propagates. Above all else, know that you’re a beautiful and significant person, period. Think about what you really want out of life, and how you can flip that switch.
Additional thoughts: When accommodating autism negatively affects your health, I think the answer is in seeking balance. You can establish a reward system for making healthy decisions throughout the week. Also, there are some psychological issues that creeped in for me - as I lost weight and mobility improved, I somehow felt like less of myself. My clothes started draping a little more, and it felt like I was wasting into a lesser form. Anyway, it was a difficult head-space to navigate, but I feel like I made it through, for the most part.