I doubt sincerely that intellectual curiosity would be a substitute for sexual intimacy. You don’t mention how much it bothers you or if you are bothered by the lack of sexual intercourse in your relationship. Your husband’s E.D. does not mean that you both cannot share sexual intimacy. It simply means that your husband cannot achieve or maintain an erection. Counseling with a sex therapist will help you to understand the many possible ways to keep intimacy in your relationship with your husband’s erectile dysfunction. If you’d prefer, you could do your own research into alternate ways to achieve sexual satisfaction and maintain intimacy in your relationship.
Intellectual curiosity, the need to see deeper into the experience of life, is a noble goal and has been the goal of all great minds in history. Perhaps, as you have matured and grown in life you have become aware of the fact that things are more complicated than they are often perceived. You may be more aware of the “philosophical questions” which have been the focus of attention, the life’s work, of people like Socrates, Descartes, Nietzsche and all other great minds.
If you could be more specific as to what you are reading, what areas interest you, then I likewise could be more specific in answering your questions. I don’t see a link between your intellectual drive and your lack of sexual intimacy, nor do I see your intellectual drive as anything negative. Many people seek a deeper meaning in life once they have sufficiently matured to the point where the mysteries of life and existence become apparent. It is possible that something else, something deeper, is driving your need to know more but it is highly unlikely. On the surface it seems that the two are unrelated and I have insufficient information from your letter to suggest anything deeper.
If you’d like to write back and give me more details about your circumstance, I will gladly provide additional insight. I hope this helps.