The inability to have an erection is not, in and of itself, grounds for an annulment. To get an annulment, you’ll have to prove some form of fraud and prove that you discussed having children with your spouse before the marriage, and he assured you that he was capable of having children and had no sexual dysfunction. This, of course, is not an easy task to prove.
As a more viable alternative, I strongly suggest that you discuss your unhappiness and desire for divorce with your spouse. Tell him how serious you are about the situation and that if he does not seek medical and psychological help, you are going to divorce him. If you have already made such an attempt and feel it is useless, I strongly suggest that you contact me at 212-370-1660 to discuss mediating a divorce between both of you.
Leonard M. Weiner, Esq./Divorce Solutions