I was banded on the 23rd, and I felt exactly the same way you do now. What I found helped was ibuprofen (if it is called the se thing in the US, it is an anti-inflammatory, just make sure you take it with milk, or something to protect your sore stomach) and the pain relief given by the doc- paracetamol helped (I think you guys call that acetomenephin). I used a heat pack on my shoulders and neck.
Shoulder tip pain (particularly on the left side) is likeley caused by irritation of the diaphragm (it travels up the frenic nerve) so every time I drank, I found that it hurt to breathe, the pain was excruciating. I found taking it very, very slow helped. I had a few ups and downs emotionally, and still am, but I'll get there.
The only other thing I can tell you is that the pain gets much better every day- I am still a little tender, but not much, and get tired, but I think I am pushing myself a little bit. The swelling has gone down in my stomach, so no more diaphragm pain, but it does mean I have very little restiction, so I am sick of the liquid diet! Not much longer though.
Best of luck, just take it easy.