How do you love your wife the way she loves you knowing that you only stayed with her because of responsibility and fear of hurting her?
You can never love her the way she loves you because you're
staying for all the wrong reasons. You're hurting her more than you
will ever know. It's doubtful that she has missed the changes she
must see in you and women are often extremely intuitive. I'd come
clean and take a sabbatical from each other for a few months (not a
divorce) and be sure you financially look after her needs and that
of any children you may have. Perhaps you need this shock to
realize that you aren't missing that much out there and can come
back, sit down, and start acting mature enough to communicate just
why you were feeling the way you were. You don't even consider the
fact your wife has issues and perhaps she craves more than you are
giving her! Communication is even more important than sex. Don't
lead your wife on any longer or you'll just hurt her more.