Oh Kay
I am so sorry that you are going thru this - I am not sure what sedative you are using, but perhaps the very could prescribe something that lasts a lot longer - I used dormosdedan in a pinch with a first time mare that was not letting her foal nurse - the baby was kind of a preemie, and the mare had virtually no bag and itsty bitsy nipples and the foal really needed her to be still in order to be able to find them and latch on. The banamine didn't touch her, but the dorm worked for around 4 hours and with a couple of repeats of banamine we managed to get thru the first 36 hours. My vets said that we could have used the dorm again too if necessary. I wonder if all the milking her out has made her nipples sore - I would imagine that a foal nursing would be a lot different than the touch of a human and this might be increasing the problem. Most touchy mares need a separation wall between them and the foal to make the the baby is OK but that the bonding can still happen over the wall. I know that with the arabian farms that I have been in attendance with they use a short wall and push the mare up agains the wall so that the foal can nurse under the wall, but the mare can still nose the baby and HOPEFULLY get her maternal attachment.
The mare that we had trouble with really took a couple of weeks before she totally bonded with her foal - and out in the pasture she couldn't care less about where the baby was - even when one of my other mares was acting as "Godmother" the mare was still pretty detached about the whole thing -- now tho, she is a great mom.
Stressful times, that is for sure -- good luck Kay, I hope things smooth out for all of you
Stac