Refusing to sign non-compete - wrongful termination?

3 years ago, I came from a long employment situation (business closed) to a new company and brought many longtime customers and the resulting business. That's why I was hired. First employment agreement (3 year limit) did not have a non-compete, although new boss did try to add it in later. With the end of that employment agreement, the new one he wants me to sign now has a very broad and restrictive non-compete - does not include things like geographical limitations. Additionally, it prohibits selling to ALL customers contacted throughout 3 year employment - including ones that I brought to the company. Besides that, he is instituting new charges to be taken from my commission, to the point where I cannot sign the entire agreement and he may very well terminate. Would this fall under a 'wrongful termination?' I understand trying to prevent unfair competition but what constitutes 'fair' and 'unfair'?