I'm losing her.

I have been with my spouse for 10 years and we have two children. Allot of issues going on but the one question I need to ask I am hoping a woman can answer. My spouse made a comment to a friend of mine that after my vasectomy (about three years ago) I don't seem to want to have sex with her as often. I seem to be the one to initiate anything sex and I am puzzled that she would make a comment like this to anyone. I have even been turned down at times sometimes two nights in a row.

Lack of sex is a symptom not the problem. Communication is your only answer. Only she can answer your question. Have a talk with her, and if it becomes too difficult suggest couples counseling.