My employer is trying to force me to resign through extreme micro-management

I was hired as a mid-level Manager. I was then subsequently given the responsibilites of my previous Director without a promotion or pay increase; i.e. the scope of my responsibilities changed dramatically.

I've been with my company for five years and been an exceptional performer throughout. Last year my previous boss was ousted by the CEO and I was assigned to take over in his role. I did not receive a formal promotion or pay increase but saw my workload quadruple overnight. My number of direct reports doubled. I was tasked with meeting a specifc business objective, which required the use of my full staff. However, over the course of the year, my staff was cut in half due to resignations (one for maternity and the other poor performance/disatisfaction) and the CEO/company was unwilling to hire replacements for those positions. This made it impossible to achieve the desired objective, yet I was still accountable. I was then taked with picking up the additional workload of those two former employees. Regretfully, without approriate resources we did not achieve the specified business objective. I have been transitioned into a new role, but it is clear that they are attempting to force me to resign through harsh and unjustified micro-management. I do have a non-compete agreement. My current employer realizes that I will be a threat to them should I join a competitor and thus they are trying to make me as miserable as possible so that I will resign and subsequently the non-compete will have greater validity, than if I were to be terminated. They additionally do not want to pay unemployment insurance I am sure. Do I have a claim for constructive discharge? Also, my CEO has demonstrated preferential treatment for female employees.