You gotta have something to look forward to which is edifying and socially satisfying. You're in a great position to get into a new sport from the sounds of it, actually. Have you tried rock climbing, jiu jitsu, kickboxing, or getting into swimming? Just something that requires using your body and building confidence, giving you something to get better at, which means you look forward to actually going out and doing it.
Actually thanks for posting this. My situation is different but I'm in a rut too. Let's get better together!
Edit: oh yeah, I've got ADHD and definitely recommend getting professionally evaluated for that. Getting evaluated for mental health can help you reframe your difficulties with being effective, thus alleviating some of the guilt and shame, making it easier to stick with healthy habits when things don't go how you intended, which is inevitable but ultimately not insurmountable.
How To ADHD is great, her videos are informative and uplifting