K.D.
Hi,
Are you sure breastfeeding is contraindicated with the medicine you need to take? The majority of providers are ill informed about breastfeeding, they get very little (if any) education about breastfeeding in med school, so tend to give a blanket recomendation of weaning. Have you looked at the book or asked your provider to check Medications and Mothers Milk by Dr Thomase Hale ? He has a website that is quite informative also. http://neonatal.ttuhsc.edu/lact/index.html
There is a huge developmental leap (Fussy stage!) between 5-6mths, and changes, especially big ones like weaning and you starting work are going to very difficult on a your baby around this time. Check out this website for great info about fussy stages. http://www.geocities.com/hedracita/Fussy_Stages.html
I'm sure you know (if your medication proves safe or if there is an alternative) that breastfeeding doesn't have to be all or nothing. Your baby can get formula during the day (if you can't or dont' want to pump) and still nurse when you are with her, your body will adjust to the new schedule. When you do wean, try to avoid a fussy stage, and also try cutting out one feeding a week, starting with the feeding your daughter is least dependent on. Good luck!