My best friend has very severe ADHD, and his partner does not have it.

How they do planning is his non-ADHD partner (who happens to have a very good planning brain) will basically defines a series of questions that only ever address a very small portion of the task at once. So instead of phrasing open ended questions like "What time do you want to go meet Ryan?", they'll ask things like "Do you want to meet Ryan at 1pm or 2pm?". It a very small change but it helps him break down the decision paralysis that ADHD creates.
It doesn't necessarily address the feeling of letting the other person do all of the planning though- to some degree, that's going to have to be something your partner is comfortable with, unless you yourself can find ways to break down your own decision making into those tiny bite-size chunks.

It sounds like you want planning to be fun or enjoyable. Do you think you might be better at it if you accept : this is going to suck, I'm not going to like it, but it has to get done.

If I wait to feel motivated or to think I'll enjoy something it'll just never get done.

Planning with a partner under these conditions isn't great. I end up pretty agitated and just want to get it over with. Maybe try to divide and conquer rather than plan together?

Maybe you take the less fun parts so planning doesn't ruin any of the trip for you. She can plan the fun activities, and food/reservations and you can plan the actual travel and maybe accommodations?

Another thing that helps me with this kind of thing is I'll set up my laptop and notebook right next to my relax spot on the couch. I don't have to do the work right now, I just have to get everything set up. Then, later when I'm on the couch, I'm more likely to actually do the research because I don't burn out getting everything I need / all set up.

My general strategy is to break it down into multiple tasks, and keep breaking it down further if those tasks are still too big.

You might find this tool useful, it uses AI to take a large task and break it down for you. You can keep breaking down each task as far as you want and with as much detail as you want.

You mentioned needing to find and book hotels, and here is what it gave me:

Find and book hotel for vacation

• Research available hotels in desired vacation location

• Compare prices, amenities, and reviews of different hotels

• Select the most suitable hotel based on preferences and budget

• Check availability for desired dates

• Book the chosen hotel either through a website, phone call, or travel agency

• Provide necessary information for the booking (name, contact details, payment method, etc.)

• Confirm the reservation details and receive a confirmation number

For me stuff like that really helps on big tasks that feel intimidating or overwhelming.

Does your partner want help planning or are you just trying to pitch in? I don't mean to sound dismissive but if your partner wants to plan everything then just let them. Now, of course, if they want help I believe you should. :)

I remember when I had to book a plane ticket, I seen it as saving moneys by doing it earlier. Then set yourself a deadline, over stress about it, tell yourself you must book it before then or the trip won't happen. I do it with myself about tasks, and sometimes it works. Sure it fuels anxiety, but well, it's not like we was'nt already swimming in it...

This doesn't sound like an ADHD thing. I have it and my GF doesn't, but I still do all the vacation planning. I like getting the most out of my trip while she just goes with the flow.

Recently planned a trio to a convention.
Looked on some page for a location to sleep, found something I liked and booked it.
Probably not the cheapest but I was kinda late anyway.

Meanwhile my mother (which I live with) basically plans the whole trip for ~10 days.

On the one hand I hate surprises on the other I hate planning too much and being restricted.
Gotta choose the poison :/