@don73
Sorry to hear your cancer is back. I found the mastectomy to be way way easier than abdominal surgeries, at least for me. They'll likely give you a 3 day anesthesia pain pump so no pain those 3 days, but it wasn't unbearable after that and I can't even take pain meds. I did have my arms freeze up after a few days, but physical therapy really helps with that. Most of the range of motion came back, certainly enough to do everything I need to do for daily living. I don't even notice it now. You'll do great if you just follow all the instructions. Prayers for you!

I had an amazing surgeon. Fortunately I had minimal pain. I just took ibuprofen and Tylenol. I was given a nice soft body pillow to help with sleep. Physical Therapy is a must with a PT that is trained in working with people who have had mastectomies. Wearing comfy clothes helps. Button up shirts or sweater are helpful. Prayers to you that all goes well. You’ve got this!

I am sorry to hear that your cancer came back. Mine did too. I had a unilateral (one-sided) mastectomy 3 months ago and I can tell you that what I expected to feel and what I ended up feeling after surgery were very different. My pain level was very low since I followed the doctor's instructions on taking the pain medicine for 10 days. Just Tylenol and Ibuprofen alternating and Tramadol for breakthrough pain.
I don't have any loss of motion with my arm now. My oncologist gave me a set of exercises to do 48 hours after surgery until the drain was removed and another set to continue after the drain was out. She told me to do them every day no matter how much it hurt. And that worked. I now have full range of motion! I was able to return to my power-walking 10 days after surgery. I just didn't swing my arms as much at first.

I did experience some discomfort under my arm where the lymph nodes were removed but that went away after a couple of weeks. I used a pillow at night to keep my arm away from the side of my chest.
I pray you have the same experience I did.

Pain was well controlled. I was even able to skip the Oxycodone after the first two doses. Tylenol and Advil did the trick, plus I received the injection during surgery of the drug that kills the pain for three days. The worst pain was in the armpits, but it was not intolerable.
I retained most of my range of motion post surgery. The hard part was not being allowed to use my arms so that the incisions could heal. It took me 6 weeks before I could get the last drain out and use my arms for doing chores and lifting more than 10 pounds.
It was critical for me to stick with the Advil/Tylenol schedule. I also went into surgery with good core and arm strength, so that may have helped. I agree with another contributor that physical therapy post surgery, and maybe even before surgery, in very important.