We as individuals all grow throughout life. Doing the things that make yourself happy as an individual are good for your well being. The online EA's aside... going back to school, wanting passionate sex and wanting a confident husband, these are all good things. When we make changes in ourselves or, as you say, become the person we used to be, it causes our relationship to change. It can either bend or break. A change in one partner causes a change in the other, it's inevitable.
I have asked myself the very same questions, "Is it fair for me to ask for something that she cannot give to me? Am I pressuring her to be something that she is not?"
The flip side of this though is that you have to ask yourself, "Can I exist in a marriage like this when what I want is to live my life full of passion? Is it fair for me to compromise what I want?"
So we talk with our spouses. We let them know that we cannot go on in a marriage as it is. We let them know what we want and our wishes of how it could be. They then know what we are asking of them. Then it is for them to decide. They may bend and meet our wants and desires. They may decide to not bend. The relationship could even break. We can't however decide for them, we can only decide what we can accept.
It takes time. I have been at this for almost a year now. I truly care for my wife and wanted to make it work between us. We still have our ups and downs. The doubts creep in on me still but I know I am doing the right thing. It isn't easy but it is worth it. I said to myself that I had to do all that I could to make my marriage work. If we couldn't work things out then at least I would know that I had done everything that I could do.
I almost divorced 7 years ago. At that time I had totally disconnected from my wife. I couldn't imagine ever being able to ML with her with feeling again. But you know what? She surprised me, she did respond to the thought of losing me and we started to find one another again. Slowly, very slowly we found our love and connection again.
There is always hope for a change. As long as you let him know what you are asking of him... there is hope. If he can't give what you are asking then you have to decide what you can accept or not. You are just starting your journey so give yourself time for your feelings to return.