Isolation and loneliness. No surprise there. It's the same bugaboo that anyone working alone from home must face. Again, a common problem for many who work from home without a boss to crack the whip. Hard times with no checks in sight.
Pay is usually better.
You have to chase payment. Not everyone is going to pay you merely because you tender your invoice so be prepared to have to spend precious time chasing payment from slow payers. If you don't like cold-calling, selling and marketing yourself, freelancing is not for you. A good proportion of your time will be spent doing exactly that. When you think of all the things the freelancer must do to generate business and income, it quickly becomes apparent that freelancing is really just another term for working for oneself.