EJE, the Medela Lactina is pretty good I think, so that should be helpful.

Some things I find helpful when expressing.....

Having a nice warm shower or bath beforehand
Sitting with a wheat pack on my boobs before starting (I have a lavender one)
Either holding DS, looking at him, or at a photo of him
Gentle massage of the breast while the pump is going
Don't look at what's coming out! I know it's hard not to, but I find I get more if I'm not looking
If you're not looking at DS, watch the tv, or read a book/magazine to distract you
Ummmm, that's all I can think of ATM

I have heard that it's very helpful to have bub feed on one side while you express the other. Try Baeb's suggestion of giving one side, expressing the other, and letting DS finish off the expressed side.

I think the milk you express during the 24 hours will have to be discarded. I know that's heartbreaking! If you're not sure you could always check with Rodney again.

I'm sorry you're going through this stress ATM, but you obviously need to sort your health out. I hope the scan gives you the answer you're looking for.