I feel no shame or guilt. The world runs on sex and money.
I understand it's a business transaction. Most things in life are. Your doctor, waitress, masseuse are there to make you feel good and care for you, but there is no love. They wouldn't do it for free. This is kind of the same way. In rare instances, you may hit it off and develop a relationship. But those are rare. And even rarer is the relationship that lasts for a long time. Even marriages break up.
I do agree with the idea of selling yourself short though. It is a real pitfall, I am struggling with it now and started another thread on midlife about it.