Something went wrong with my facelift and my jowls dropped completely 5 months later

What you are experiencing is very common. Skin is a live organ and as such will respond to the forces placed on it. Just like during pregnancy when abdominal skin stretches to accommodate the enlarging abdomen, facial skin relaxes in response to the tightening caused by the facelift. In most cases there is a 20 - 30% relaxation of the skin over the first few months. In a small number of cases like yours the relaxation is enough that a revision may be appropriate. I think it is very generous of your surgeon to not charge you for his time and expertise in addressing this with further surgery. Good luck

Your doctor is being honest with you and wants you to be happy and is willing to revise your surgery to try and get the best result for you.  Most surgeons have a revision policy along the lines that within 1 year, if there is an issue, the surgeon won't charge a fee but the cost of  the facility the surgery is done in will be borne by the patient.  Beyond 1 year,  most surgeons consider any further surgery as a secondary surgery and fees, perhaps reduced, would apply.