Tl;Dr:
- Get an electronics organizer bin. Raise up your bed and put it under your bed
- Clean with someone else (they don't have to be cleaning your mess)
- Have someone else tell you what to do
- Take your meds if you have any
More details:
It's hard to offer specific advice without seeing what we're working with, but you could get something like this to store lots of little components. You can also buy little lifts for the feet of your bed which will allow you to fit lots of stuff under your bed (at the cost of a much taller bed). My roommates in college loved those things.
As for actually doing the cleaning, body doubling works really well for me. My wife and I will do our separate cleaning chores, but the fact that she's also cleaning keeps me focused on my task. I don't want to be caught in a pig pen while she's made her area pristine. If you don't live with someone, you could do a video or voice call with a friend. My wife's therapist has offered to supervise (via video call) her while she does chores too. Having someone to hold me accountable really works well.
Having another person who doesn't live with you come over to your place and give you directions or suggestions can also be helpful. I have a really hard time making decisions about where and how I should store some of my things. My brother occasionally comes over, accesses what needs to go where, and tells me what he thinks I should do. I follow his suggestion as if it were an order. Sometimes we switch: I'll go over to his place and boss him around. This works for me because the wall preventing me from cleaning is decision fatigue from trying to find the perfect solution to an organizational problem. Not being able to identify where to start or what to do next also can stop me from organizing. Blindly following someone else's decision, even if it's not perfect, seriously helps. When I offer suggestions to my brother, it's relatively easy for me to do. After all, it's not my stuff. I've got no skin in the game.
Of course, someone has to be willing to help you clean like this. Don't force them into it. Make sure they know what they're getting into.
Finally: meds. If you have them, use them. I've found that my meds will keep me doing what I was doing before I took them. Don't wait for your meds to kick in and then start cleaning. Take your meds, start cleaning something that's easy and mindless (for me that's doing the dishes), and by the time your meds are in your system, you'll be more motivated to tackle something bigger.
Everyone is different. Some of this advice might help. Some might be worse than useless. But my therapist always says, "If what you're doing isn't working, try something different. Just 'trying harder' to do the same thing over and over doesn't work with an ADHD brain."
Sorry for the wall of text. Good luck!