Every since we moved in together he doesn't seem to be interested in having sex. He is in law school and has a lot of studying to do but I don't know how much of that has to do with anything. When we talk about it he says that since he has me next to him all the time he is satisfied. Also I went through his computer and found that he has been looking at porn site often. I don’t know how to take this please help!! Also the past couple of times while we were having sex in the middle of it he went limp lost his erection??

Alto for time stress can have an impact on a mans sex life. About the porn, its something that we women have to get over, its just a fact of life, unless you get a reaally strong Christian and a lot of times I'm not even sure they can resisit all the time.
However if porn is taking the place of your sex life there may be more underneath the covers.
Have you talked to him about this? If so, what did he say?

If the porn is constant, then yes it can be a problem.