I'm not a big fan of spying on ones spouse or nosing around unless their is reason to believe that they are lying about something. I don't think hes had a chance to answer any questions.
If you goto your husbands computer and look to see what kind of porn he's been looking at then what? Your going to have to confront him either with what you've found offensive or you're going to have to stuff your knowledge of what he's viewing. If you choose to stuff it you're driving a further wedge in the relationship.
I would want you to deal with the issue head on if you'd like a good screw as much as you say you would let it be known in the plainest most graphic detail what you want. If you're waiting for him to make a move you're just going to be avoiding the issue.
As far as the idea that your husband is gay I don't know what to say sexual identity is pretty difficult subject when you try to get specific in some situations. I know that it must be very difficult for women who find themselves in a situation where their guy doesn't behave in the way that it seems all guys do. Thinking about sex every six seconds and the incredible appetite that most men report to having.
An answer to the ? of "is he a closeted gay man hiding behind a screen of a hetro relationship" may give you answer to the sex starvation but maybe next to impossible to get. It may be the case and it may just be that you would like to see some more masculine and less soft attributes from him.
I don't know how you can change a person but I do know that you have got to bring your unhappiness and what your needs into to the light. I don't know if you have done this, f you have rattled the cage or if you have the energy to do so. It would be nice if we didn't ever have to these things but it's just not the case.