mampig the research into CC is that leaving them to cry in a stressful situation (ie crying alone as opposed to in-arms) releases cortisol which is a toxic stress hormone. This you know, obviously, but the point is that cortisol is something that will be released in everyone from time to time with no adverse effects, at least long term (clearly it's horrible while it's happening). So the research says that it's sustained cortisol release that's the danger. It seems that each child's tolerance is different so it's not possible to say how much is "ok" before it does cause physical problems. But it's unlikely (I mean, really, it's not going to happen is it) to be one or two nights of CC. In my opinion.
How a parent feels about doing that to their child is a different matter, and clearly something you are factoring in, and balancing with the needs of the wider family.
On the other hand, there is a no-cry sleep solution for toddlers and preschoolers if needed when the time comes :)
tickleme :( If you go to your GP and s/he suggests anti-ds you can ask for ones which are compatible with BFing. This might help www.breastfeedingnetwork.org.uk/pdfs/Antidepressants_and_Breastfeeding_March_2009.pdf.
jammydodger what treatment for thrush have you and your baby had so far? Fluconazole is only for ductal thrush (the deep breast pain) and needs to be a sustained, ongoing course. This explains it: www.breastfeedingnetwork.org.uk/pdfs/BfN_Thrush_leaflet_Feb_2009.pdf.
You do need to ensure you're not cross-contaminating the thrush. It's easily passed back and forth between you, and also passed onto your clothes and back. If possible, ideally you need to wash your bras each day at 60 and iron the back if it's ok on the fabric. Similarly your towels need the same treatment (you could use a facecloth to dry your nipples to reduce washing). Bottle teats if you use them, dummies, anything that goes in your baby's mouth need sterilising very frequently.