OH man... I so feel your pain with the being unable to be intimate. In my opinion, it's the things like THAT that make it unbearable. It's bad enough that you're in pain all the time, but when it starts messing up your personal life it's like "WHY ME????"
I have to echo the suggestions of getting a second opinion. Sounds like your doctor is missing something, to me. I know if I had bloody D that even my negligent, horrible, doesn't-even-believe-I'm-in-pain-or-sick doctor would have done a whole mess of tests and stuff to follow up on that. What you're going through sounds like HELL and if your doc isn't helping you, find someone who will!!
Have you tried meal-replacement shakes, like Ensure, Slim-Fast or Carnation Instant Breakfast? I sometimes resort to these when my stomach won't tollerate solid foods (Ensure is my pick because it's lactose and gluten free so it's easier to digest). They still sometimes make me gassy and/or crampy, but it's a LOT less painful than when I actually eat real food. Plus it helps slow down the weight-loss and keeps me getting some form of nutrition. I find that when I stop eating altogether I end up in this down-ward spiral where I get sick from not eating, so I don't want to eat, so I get sicker from not eating.