Society places role restrictions on us and sometimes it can be surprising how effectively these restrictions can limit us. In your case, society told you you should be with women. You are now finding that there is more to you and you at least want to explore other options.
Don't worry, it happened to me as well. For years I thought I was asexual as I seemed to lack and interest in sex. After my roommate passed away and I ended the grieving process, something was different. Susan's taught me about Pansexuals and now I understand. Just having somebody in my life even without sex or romance was enough to fill my Pansexual needs. I have nobody to fill that need so the need for others in my life has become clear. I do know this time I have to very selective in finding that person because once in my life, I will not have the desire for more.