This post sounds so familiar. My education and back ground is a sound engineer and electronic technician. Even back as far as high school, my dreams were to have a "stereo store".
When I graduated from college I went to work (in the service department as a tech), for a regional stereo store with 7 locations. I left there to become the store manager and service tech of a stereo store in my home town.
After some differences with the owner, I left and started my own repair shop. I was very successful with that so I figured it was time to take the plunge and open up a "stereo store".
This would have been in 1980. The lines I had were Harman Kardon, Denon, Tandberg, CM Labs, B & W, Rodgers, Polk, among others. By the mid 90's I was close to having to file bankruptcy.
I closed down the retail part of my shop and went back to strictly servicing. In the early 2000's it became evident that the repair business was going south as well. Equipment had basically become throw away. The ratio of out of warranty repairs to in warranty had completely flipped. As a result, it was time to change career paths and I started a new business.
The business was very successful. With success I had developed an exit plan (as I was 10-15 years out from reaching retirement age). About the time the exit plan was to go into effect in the early 20 teens, the buyer decided it was too much work, left and changed career paths for another job.
Now I had to find another buyer, and COVID hit. Business fell to 17% or what it was. Luckily, I eventually found a buyer, was able to sell at a reduced price, but I am officially retired.
In regards to your situation, a couple of points to be made. Everything you knew about business from you previous experience, it is not totally irrelevant, but mostly.
The Pandemic changed everything, and it will NEVER go back t how it was. Web presence or not, you will not compete against the Amazons of the world. The Pandemic allowed Amazon to become the "go to" shopping place, and that is ingrained shoppers habits, and habits are hard to break.
Others have mentioned cash reserves. Very valid. Unless thing have changed, vendor have "opening order" requirements, and there is a $$ amount buy in, and then you have to do so much each year to keep the dealership, and most want the line fully represented (no cherry picking).
It is fun and very fulfilling to educate people about audio, but that portion doesn't pay squat. Most people will go for the best price, even a few dollars. No business is rock solid any more. Who would have thunk Sears would be where they are.
You can work you ass off (as I did with 70-80hr weeks), and in the long run, while it keeps you afloat, it doesn't seem put anything in your bank account.Believe me, I'm talking from experience.
The long and short of it is, you are going to do what you want, but if you want to save yourself the stress of wondering how you are going to pay the bill, buy or collect audio equipment for your own enjoyment, or go t work for someone else, because the stress gets in the way of the joy and fun.