Hi Gary. It certainly sounds like you've got a lot on your plate!

Rejections can be tough, especially when you put a lot of effort into putting your best foot forward. Try to reframe it as a learning exercise (without textbooks, etc). If you have access to feedback, ask for it and try to incorporate it into future approaches.

In some cases, rejections can also be a blessing in disguise. There could have been aspects of that job that wouldn't agree with you, e.g. working culture, team-fit, or something like that.

Multi-tasking is actually really difficult. If possible, try to focus on doing as little things as best as you can. I know it's easier said than done, but spreading yourself thin takes time away from other tasks.

And most important of all, be kind to yourself; take regular breaks too. You don't want to let burnout set in.