It is important to be informed and to inform your practitioner about how you are feeling. There is a saying: “Sometimes the pain gets worse before it gets better". However, it is important to speak with your practitioner so he can modify the treatment accordingly.
Reducing the duration, Electro vs no electro-acupuncture, need to be explored in regard to the therapy. Laying down with or without a pillow if working on the back, knees more support... Maybe sitting is a better position for you. Please, communicate with your practitioner so he can explore how he can better assist you.