I'd agree with the advice above that exclusive expressing should be a last resort, however if all else fails it's a way of getting breast milk to your DS. Have you read the Exclusive Expressers sticky? As an EE I read it a few weeks ago and it was great to read others stories. It's certainly not the easy way to go and I dare say more of a challenge with another child. Hopefully the sticky will help you weigh up your choices.

Good luck with it all.