I had my surgery when I was 46, and I was still a little overweight--maybe twenty pounds (of course, I lost a few pounds in surgery

). I've never had a very strong immune system, and I tend to be a little slow to heal. So I expected my body to recover slowly from the surgery, and I think it did. I was taking naps for weeks after.
Three weeks after my surgery, I volunteered for Pride weekend, both days. That was the first time I didn't take naps in the daytime, and I was wiped out afterward. I took a few naps in the days following, but I was done with naps in four weeks or a month.
It sounds like you have had quite a lot on your plate, so it's good that you'll be in a clinic for a few days with pros to take care of you. Enjoy it! There's no shame in feeling a bit alone when you don't have a partner or a family member to be there for you. Humans are social creatures, and we feel much safer when familiar people are about.
I guess I was lucky. My partner broke up with me about eight weeks before surgery, and he absolutely was NOT comfortable with my decision, but he was true blue and took care of me until they removed the drains a few days later. The expression on his face--closed off, full of repressed pain--still haunts me when I think about it. Sometimes I wish I'd had professionals take care of me during that time. But mine was an outpatient procedure.