When medicated I feel like it’s easier to stick to a task, but it doesn’t help me with picking the right task so I think I understand some of what you feel. The Time Timer has helped me sometimes when I just need the extra bit of external help. The act of picking it up and deciding to use it helps reaffirm my intention of working on a thing, and then the visual indicator of time passing helps my really really bad time sense to be moored to reality a bit better. The mental UHG of beginning the work task seems to melt away pretty quick after that initial step. Then the medication helps to let me proceed without my mind wandering. Other stuff is a necessity like physical activity and enough sleep. Getting out of a misdirected focus is tough, so I feel for ya.
Whatever happens, I hope you two can get back to hiking without the madness. There are tons of ways to address it tactically that others have gone into, so I won’t make any additional suggestions but I can say that as a diagnosed adhd-haver I can super duper relate. I hope you get the diagnosis outcome and support from your partner that you need.