I hope you find a solution.
With my DS, my placenta would not separate. I had the injection as he was crowning and put him to the breast, but nope still didn't budge. They gave me the injection agaian and the Dr tried gentle tugging, but nope. They then tried pushing on my tummy and ice/heat packs, then even used a catheter to empty my bladder, nope, still no luck. After an hour and a half (

i know, long time to wait) they suggested i go to the loo. Well the walk there and sitting for a couple of minutes did the trick. I did however end up having the injection again as I was showering as I was still passing clots and then put on the same treatment as c-section women later that night as my uterus had decided it had done it's job after delivering bub, and refused to contract. I was borderline of a bllod transfusion, but ended up on iron and vitc tab 2 times a day for the next 2 mths instead.
Whilst pregnant with my DD, I mentioned all this to the middies and was told that given my history they would administer the injection via an IV bung in my hand as it was stronger than the injection into your thigh. I didn't get the chance to find out if this would work as she was breech, so delivered at 39 weeks by CS