The main thing would be to explain that it was medical, that it is over now and you are healthy again. The fact that it went on a few more months than necessar

The main thing would be to explain that it was medical, that it is over now and you are healthy again. The fact that it went on a few more months than necessary isn't really relevant, although saying that you took a few extra months off at the end just to refresh yourself does reassure that the health issues are, in fact, all over. It might be worth practicing, alone in front of a mirror or something, explaining this. It may or may not get asked, but if it is you want to have your verbiage ready. But health issues are not rare, and wanting to take time off because you have the money to do so, is not something most people would have any problem understanding. I've known several people who did that, and they all got employed again later, without too much trouble.