1. You are clearly working as a contractor, this requires a lot of financial discipline, why do you not have enough runway saved up to deal with this? From personal experience working as a contractor I always ensured I had 6+ months worth of runway.
2. This title inflation is really scary. You are not the CxO of anything if you are a contractor. Unless you mean you are the CxO of your own company through which you contract. However even then the way you conflate your own position in your own company and the role you fulfilled at the client does not inspire confidence.
It is truly terrible that you are in this situation and it is honestly a very horrible thing for this company to do. Either way if it does not breach the contract they have with you then there is nothing illegal about it.
At some point we all need to take a very long hard look at ourselves and realise that crying foul when the wheels come off life is not the answer. People set themselves up to not be able to absorb the terrible things that can happen in life. Some general advice that should serve anyone that is contracting well is:
1. Don't live above your means! 2. Save at least enough money to carry you through 1 year of living expenses should you lose your current contract. 3. Always keep a close eye on the contract market and move contracts regularly. That keeps you interview fit and aware of current demand. 4. Realise that life is not fair and plan for it! Not only do you sometimes get terminated by an employer (rightly or wrongly as they might simply not need your service anymore) but you could have an accident tomorrow that puts you out of work for months. (Believe me I have had such an accident and if I did not follow rules 1 and 2 I would have not been able to relax and recover fully before needing to rush back to work)
Best of luck and I hope that the lessons of this experience does not pass you by.