Hi I had mastectomy with implant expander last August. The anaesthetic was amazing. I barely felt the needle go in, then I drifted off to a lovely sleep. I came round in the recovery unit and went to the ward. It was a bit sore and they gave me morphine. I went home the next day with a drain. There wasn't too much pain from the wound and the implant looked great as they partially inflated it. I'll be honest, the drain was uncomfortable and a pain to carry around. It was out in a week.after that, I felt pretty good, but very tired for a few weeks. I am due to have the tissue expander replaced with silicone and then silicone on the other side, to match up, in a week. I was a 32AA but will be a B cup afterwards.
My advise is, put your faith in the hospital team, they are amazing people, rest and allow others to look after you, eat plenty of fruit and vegetables and focus on getting well.
Your skin will stretch to accommodate the implants, so don't worry about that. Seroma was not an issue for me.
Good luck, you will be fine.
Zu