I am an exempt employee. I hold a director position and I usually work 45-50 hours a week. 6 months ago my supervisor asked to take an additional responsibility to manage a totally different department, because there was an emergency in that departent and

I am an exempt employee. I hold a director position and I usually work 45-50 hours a week. 6 months ago my supervisor asked to take an additional responsibility to manage a totally different department, because there was an emergency in that departent and previous director was fired. the gave me the tile of interim director, but there is not search for new director. Now I am working two jobs, one for which I was originally hired and the interim position. I am now working between 65-70 hours a week and I do not have a life anymore. I know I am unable to claim overtime, but there is a direfence of working few more hours a week and working to dead with not additional compensation. What are my legal options? Can I just inform my supervisors I cannot the second position anymore because I affecting even my health?