Dream, thinking of you and your poor DD. And your ill babies too. 
All this mention of dealing with two (or three) at once is scaring me slightly. Inconsistently, because I am v broody at times. However, it is one thing me being broody and quite another when DH starts being broody too and saying he thinks we should ttc in January! Quite frankly, going back to work in January is occupying all my head space and the last thing I want is something else to stress about! January, ffs, of all the months he thinks would be appropriate. Sensibly and financially, we should wait until next Oct so M is 2.3 or older when the new baby comes along and is therefore 3 when my next mat leave finishes and we have to pay for 2 at nursery. Less sensibly, I could be persuaded to move ttc forward a few months just because I'm broody too. But not 10 months and to a month in which I am returning to work, we're both starting compressed hours and, most importantly, M is starting nursery which she might hate. Plus it feels like taking the piss, a bit, to return to work and instantly get pg again (assuming I would, which is naturally not certain at all).
Which leads on nicely to stress no 2. KIT days. We're broke, so it would be helpful if I did some keeping in touch (and getting paid). But what do I do about bf? Express during the day? Not express, just keep changing breast pads? I'm scared of the thought of expressing at work. I'll be in a new office when I go back, and I don't know where the statutory bf room might be. What I do know is that the whole bloody place seems to be made of glass, some frosted, some not. I don't know if a bf room has to have a lock on the door so you can be sure no one can walk in on you. Does it have to have a fridge? I'm not that good at expressing quickly, or without getting milk all down my front. That's before I even start to try to work out a babysitter for M. My mum is the logical choice except for the boisterous dogs issue and the fact that she's moving to Aberdeen at the start of Nov, and realistically I'm not going to have organised a KIT day with work before then.
Stress no 3. Actually going back to work. Jaggy, I know you're wrestling with this one too. How old will R be when you go back? M will be 10 months - what happens with milk? I'm not keen on M having formula (please don't be offended, ff-ers), so does that mean that I need to express for her until she's a year old, or will she be able to get by on food and water? I mentioned the possibility of expressing to DH and he was weirdly repelled by it. He thought I was being ridiculous and martyring myself. I don't know why he had such a strong reaction. 
Sorry for the mind-dump. It helps me to write all this stuff out. Feel free to ignore me!