Sorry you are feeling this way op. You sound overwhelmed.
We all fail and fail often. I'd go as far as saying that failure is essential to learning. It tells us we have taken on too much. Or we need help. Or we need to change the way things are structured or how we approach them. And we often judge ourselves much more harshly than others would.
Can you try and pinpoint the one significant thing that is making life most hard for you ATM? And would make the most difference to you if it changed?
Is it sleep? Or your weight perhaps?
Then could you take one small step towards tackling one tiny aspect of that one thing?
Break it down in to very small gradual steps.
We all have times when we are brought to our knees by everything being hard all at once. And it's ok to take your time, put everything else aside, and just focus on one part of one issue to try and improve things for yourself, very gently, one step at a time.
If a close friend of yours was experiencing the same issues, how would you advise them to proceed?
Do you have any RL support? Friends or family? Could you talk to them and ask for help? It's so hard to ask for help but if you ask for something specific like "I am desperate for sleep, would you mind baby-sitting for one afternoon so I can catch up? " then people are often happy to oblige. But that depends on you being open about what is troubling you and how they can help.
Or if it's weight, don't think about it too much, or put too much pressure on yourself, just start by going out for a 15 minute walk, and then swap out one sweet treat in favour of an apple. Start slowly.
Good luck op. Hang in there. I hope you can find a path through all of the problems 