Isolation is common when you’re freelancing – no more coworkers, no more water-cooler, no more guaranteed daily interaction with others. For some, it’s fine. For others, it’s torture.
Even if you’re more introverted or you tend not to need a ton of social interaction to feel ok, you do need some interaction with the outside world if you’re going to stay mentally balanced. And don’t think that the people (and animals?) living under the same roof will give you “enough” interaction, day in and day out.