Dump his ass, the 2 of you will figure it out together.

I think if you’d start landing projects and having them delivered; customers would want some tweaks. Is that something you want to do as a company? If not, how thorough does documentation need to be for someone else to do it and does the required time for that fit within the 999 dollar price?
Say some of those MVPs are succesful and customer wants you to build the actual project, since you’re already involved; same questions.

To save on ad costs; maybe visit a few networking events, see if you can find some clients there?

Am a project manager myself, always having multiple projects at any given time. I have blocks of activity in my outlook calendar. Catch-up on stuff that I didn’t get done the previous week / new in my inbox that need immidiate attention on Monday mornings. Some meetings in the afternoon.
No-call Tuesdays, partly because I have my son at home in stead of daycare then, which allows me to do administration stuff. Wednesday I have half a day calls with customers/stakeholders for updates and such and half a day for actual work. Thursdays I have a lot of internal meetings, with colleagues and to optimize processes etc, which should lead to less pressure in the future. Fridays whatever needs doing / socializing.

I also have a 10-15 minute cal with my team everyday just to see what everyone is up to, if they need help etc (stand-up call).

Other than that, the difficult part is to have the discipline to do what you scheduled time for, also meaning telling people ‘not now’.

You’re looking for answers in the wrong places. A startup that makes soda isn’t looking directly at Coca Cola’s revenue (although, sure, it gives you an idea of the potential market) and considering how you want to present a fix to home renovation thing, I’m not sure looking at disposable income is the right metric either. It may get purchased by a professional/contracter for a project. That may also be a better way to sell whatever you have in mind.

But, that is assuming there is actually a need for your solution. an MVP can help there.

People that want quality tattoo’s have no issues finding quality artists. People that don’t care about quality, won’t make the effort of whatever you have in mind and just go the nearest/ask their buddy with a diy kit off of aliexpress.

Just get in touch with some of the people you talked to before, ask them how they would do it or like to learn about your idea. They may appreciate you asking them for their input or even help you.