PIO and Vasovagal Syndrome (Fainting)

I’m about to have my first FET using an adopted embryo (I haven’t ever gone through an ER), and I am stressing about the PIO shots! I tend to faint during blood draws and during painful medical procedures/events, and sometimes even just when I’m anticipating pain. My husband will be administering my shots, but I’d love any advice on how to minimize the pain, and any tips on how he can administer shots while I’m lying down. If I’m lying down I usually don’t faint, but if I’m sitting or standing when I get a blood draw I will pass out 100% of the time.