Hi! Good luck with your donor experience, and that's fantastic you may be part of a 9 person chain. I agree with te other donors who've said everyone responds differently. For example, my mother (who was the recipient) gets extremely nauseous when exposed to anesthetic, and my uncle who had abdominal surgery had hallucinations as a result of the pain medication he was on... That example is a bit extreme, but his wife is a doctor and was able to explain it to him quickly. For me, I had a little bit of blurred vision. So, it's just important to be aware you could react a little differently and listen to your body and don't panic. I think it's good to at least have some idea of what to expect going in so you can plan accordingly, or at least I found that to be true for myself.
I try to avoid unnecessary medication and painkillers because I kind of figure, if I don't really need it or can achieve the same result, why put something else in my body? I didn't get much nausea after the surgery, except when I begged for ice chips because my mouth was so dry it felt like sandpaper--that made me nauseous and vomiting was even more painful right after surgery. So...be careful with that...it was a little bit of "solve one problem, create another." Also, be aware you may have throat pain from being intubated, so it's okay to ask for cough drops or have a friend/family member keep some for you.
While I was in the hospital, I took the prescription pain medication when the pain started to get uncomfortable to the point I didn't want to move. Otherwise, if you wait too long and the pain really kicks in, it gets too difficult to move around at all, which will impede recovery time.
I spent three days in the hospital (because of a minor complication), but after I got home I only continued to take the oral painkiller (can't remember what it was, sorry) for another day. After that, I switched to extra-strength Tylenol and I didn't even take that for very long. Moving forward, I just went at my own pace and tried to improve my stamina every day. As for the "tired for a year" question--I was nearly "tired for a year." That might be an extreme way to put it; I'd say that I "tired more easily." Many, many people have told me they "felt totally fine" after 3 weeks, which in the past made me embarrassed to admit it, but regardless of what people/doctors say I think it's important to know it is a big trauma to your body and for some people can take longer to recover--I wish my transplant team would have been more clear about that part, but I was 27 when I had the surgery, so considered a "good candidate" for a "quick recovery." That's what they kept repeating to me, so I was surprised when I had a longer hospital stay and recovery time.
So my advice would just be to stay open-minded but aware of options and possibilities and be aware of your body and your reactions and adjust accordingly. I'd also recommend using pain medication when necessary so that you're not so uncomfortable you become immobile or lethargic--you have to find a balance.