You totally can do porn. Don't think we are much different in size and I have done porn. Not a ton but that was my choice because I honestly hated it. It is NOT hot to do porn, not at all. Think of it this way, each 15 minute scene in a porn is about 2-4 hours worth of work. In that time you are standing there naked, starting, stopping etc... There is nothing about the actors enjoyment, it is simply getting the footage they need for the vid. Remember in straight porn too, the guy is very secondary and paid very little. I didn't hire an agent, I was asked by a director.
Do I think you can do it, YES. I think though you would probably get more enjoyment off doing web cams shows etc. If you want to do porn to fuck hot chicks, you will get to but it will be the most non-sexual sex you ever had - if that makes any sense at all.