Is this a case of breach of oral contract?

For the last 6 years I have been a manager at in a small business that has a medical marijuana provisioning center, certification center, magazine and home and office rentals. I was directly under the owner and handled HR, payroll, taxes and running each area. In 2018 Michigan changed the laws and every marijuana facility business had to be licensed, I handled the bulk of the application process that took close to a year to complete. Due to past issues, the owner of the business was not allowed to be licensed so he sold the business on land contract for 1.5 mil. The new owners asked me to stay with the company and the old owner wanted me to quit and go with him to his new venture. I stayed because the new owner said I would have more opportunities with them. The business was required to close while the licenses were issued and inspections took place. It was closed for three weeks and we did not recover our customers. Product was impossible to find and expensive, For the next year, I was left with no help while trying to keep the business from going under. I asked the owners at least twice a week for money to buy product. We were barley making enough to cover payroll. I was unable to cash my paychecks for months at a time due to no money in the accounts. I had to use my own money to pay for items needed. I made deals with growers to get product on terms, setup licensed home delivery and other things to start making money again. The owners would tell me daily how good of a job I was doing and how they really needed me. The owners asked me to help them with another business that owned. They promised they would pay me extra for helping, They said that I would make more money that I ever had in my life. I told them that I had been promised things from the old owner but i never got anything, They said that they would never do that and if they say that they will pay, they will. I never saw a penny from all the time I put into that company. In the beginning of 2020, the owners wanted me to process applications for 3 new state licenses. The applications are vey intensive and companies pay thousands of dollars to have them processed. The owner told me that I would be running the entire complex, a grow, processing center, adult use and medical marijuana stores. We discussed this for at least 30 minutes. Due to this discussion and guarantee of a long term job making more money, I financed a car. I have not had a loan on a car for over 15 years. In May of 2020 my mother passed away. I was out of state for two weeks. When I returned the old owner was back and in charge of everything. The new owners never paid him for the business, I spoke to the new owners and they told me that they were never going to pay him for a failing business. They told him they would make him a partner and he could run the business again instead of paying him. I was not told that I was no longer the manager and most of the policies I put in place were changed. I came back to just being an employee. Now I found out that they are going to fire me as soon as all the licenses they want me to do are complete. I don't know if i should quit or wait until I am fired I feel that this is a breach of an oral contract.