You certainly have a lot on your plate. It’s completely natural to emotional about your son’s diagnosis and the amount of care he needs. You will feel much better if you banish the guilt of what you haven’t accomplished, validate and work through your feelings, and make every effort to maintain a positive outlook as much as possible (Of course, there will be days when you just need to grieve).
It would be helpful if you could come up with a daily system for managing all your to-dos. While there are fancy planners and never-ending possibilities in apps for to-do and time management, it could be as simple as a spiral notebook with an ongoing list (I had a boss years ago that used this system — she kept a running bulleted list in a simple, cheap spiral notebook. She carried it with her everywhere. Everything went on this list. When completed, she struck through it. Every morning and the beginning of every afternoon, she’d run through what was left to be done and prioritize and tackle one at a time. When she started a new page, any lingering to-dos on the prior page were copied to the top of the new page, so all items were always visible.) You could accomplish the same thing with a dry-erase board too.
The two articles I posted higher up in this thread are really helpful too.
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism