You will meet lots more people staying at uni, there is less of a social aspect staying away.
It depends on the transport but going out in the city, you might not be able to get home from a night out easily, but it won't stop you getting involved in societies and clubs.
If it was just that you were apprehensive about living away, I would suggest that you just relax and do it, as everyone else is feeling the same. However if you need to recover from this operation it might be for the best staying at home. Don't use it as an excuse however, these are some of the best years of your life.