I'm at my wit's end and I really need help, guys.

I have deadlines that I'm incredibly overdue on. I have application deadlines coming up for jobs I know I will like and that I can actually feasibly get. I just have to write a few essays and applications. Should be easy, right? Fucking nope. I've dragged this out for weeks/months, and it's reaching a point where just the amount that this stuff has dragged on is making me anxious.

The two biggest problems I'm facing are: 1) it takes me hours, half the day, to even start work, and 2) my ADHD leads me down mental rabbit holes and before I know it it's 3PM and I haven't done shit, and it makes me so anxious.

For #1... I'm working on that. Hopefully gonna try getting up earlier tomorrow. I'm aware it's gradual. I'm also working on the gradual solutions for #2 but I really need something in the short term too, and I'm so lost.

What happens is: I get up. Usually late. I start work. I often manage to exercise/etc., but that means I'm starting work at around 1-2PM. I look at the clock and I get anxious. I suddenly can't clear the "there's not enough time left to do anything!" thoughts from my head. And there's my whole day fucking gone.

The only thing I can do to get less anxious is get the fuck out of there, resign the day to being wasted, and say "I'll try again tomorrow." But that's not a viable solution! Especially not when it's very feasible to get work done at 1-2PM! I hate myself so much for being bowled over by these minor doubts. But I can't stop them. I need something to stop my racing mind. Because even when I'm not anxious, my ADHD will make my mind circle and I'll dive down some stupid rabbit hole looking for electric kettles or reading about Mansa Musa (both what happened today instead of work), and I'll do things that will make myself anxious!

A big trigger is often sunset. Which is around 4.30PM right now where I live (Canada). My brain sees it getting dark and if I haven't done anything that day, even if it's not late, my anxiety will immediately spike, like clockwork. I'll immediately start mentally punishing myself.

Do you have any "mental re-centering" activities/routines that help you notice when your thoughts are going out of control and calming them down? Mantras or exercises or anything? Literally anything that helps to quell anxiety. I do some mindfulness routines right now but they've been helping less and less as of late. Not necessarily looking for long-term solutions like switching meds (I know I need to think about those!), but looking for stuff I can start/try on a daily basis. Not expecting any miracle solutions... but I'm just fucking out of ideas. So tired of hating myself and my own brain for this shit.

For reference, I'm on Vyvanse right now (60mg per day). I try to take it as early as I can, although right now that's often, like, 10AM. It does noticeably make me calmer for a while, but the whole thought cycle of "it's too late and you can't do anything before sunset!" often overwhelms the calm that Vyvanse brings. I also try not to drink caffeine after 3PM or so -- before that I have one or two cups of black tea.

Any advice would be greatly appreciated! Thank you!