Julius Caesar was so deeply in debt in his 30s that his creditors tried to stop him from leaving Rome. He left anyway, went to Spain, conquered it, and came back rich and powerful.
Yes, you can start all over again.
You do not need to know everything to start.
You need to be willing to learn everything that matters.
Marketing.
Sales.
Customers.
Finance.
Operations.
Hiring.
Leadership.
The founder role is not one skill.
It is the willingness to keep becoming the person the company needs.