Please don't be hurt because your husband wants to masturbate while looking at porn. That in itself does not have to set off alarm bells, and it's not a reflection on you.
However, it sounds like you want some of the passion that he is directing at the porn. And that is a problem!
His denial/lying is troubling. Do you think he is just embarrassed at being caught, or do you think there is something more he wants to hide?
Is he looking at anything illegal? Is he spending any money on it? Is he downloading it at work? Those would be problems too!
Whether this is plain selfish behavior, addiction, or something else--that's a complex question, one probably best left to a qualified professional. But don't be afraid to go to one, even if your husband won't go with you. You need support, and your husband isn't giving it. Good luck...I think I can say we are all pulling for you!