Can't speak to the specific of what I'd consider a large .."small" business, as my own small business consisted of myself and two sons... building a framework for a franchise. The dynamics were much different, but the personal part of extricating from a commitment was in same ways similar.
In my case, a health (colon cancer) scare forced the separation because I didn't want to leave my DW with the substantial debt associated with a start up.
We were in business for three years which effectively meant full dedication to the many extra hours of developing and planning. In effect, an all in, personal commitment.
As I was incapacitated for three months, my sons were left with the task of phasing out, and closing down. Definitely an emotional situation, with much anxiety.
The good part...
A look to the future. A life changing event. A mental closing of the door to where we had been and where we were going. This is BIG.
Since we weren't sure of our future (future recurrence of the cancer) it was a fresh start, with no assurances of how long we'd be here. The decision to retire wasn't easy. Always the worry about not having enough to be able to stay retired. At age 53, it was a chance. Many money scenarios, but the saving grace was the idea that if all didn't go well, we were young enough to go back to work... full or part time. The safety net that gave us the courage to make the decision.
About the mental angst:
Most of my own working years were spent in relatively high stress jobs. It was a challenge to shift from that, to the idea of a more free lifestyle. To shift from running the show for others, to the idea of making the most of the years we would have left to live.
It took a little while, (perhaps 3 or 4 months) but we made the change... and the results were great. Sudden freedom from anxiety and a whole new life to be built from scratch. We channeled the energies into planning for happiness. That was 27 years ago, and now, in our 80th year nothing has changed.
Advice?... not mine to give, but a guess?.. A very short time to adjust to the new norm. Looking ahead is inspirational.
Best wishes for your new life!