Welcome to OCF. It can be very frustrating to the patient when they are not instantly back to how they were before they had cancer. Since your father only finished treatments a week ago, he does have a while to go before he recovers. Tell him to take things day by day. the better his nutrition, the faster he will bounce back. Make sure he gets a minimum of 48oz of water and 2500+ calories daily. He needs to keep swallowing every single day too or his muscles could 'forget' how to swallow. Much easier to struggle by taking small sips several times per day than to relearn the whole process. Most patients will begin to feel a little better after 2 or 3 weeks post radiation. Its a long process but healing will happen faster if he adds some high protein powder to his daily formula. Have him do small goals every day. Maybe walk to the mailbox for a couple days, then to the end of the block building up to going around the whole block. This will help him to see he is making progress. Some patients (and caregivers too) suffer from depression and need counseling and anxiety meds. Everyone is different and will respond to everything in their own unique way. Do the best you can to be positive around him. Make sure you always take a few minutes everyday for yourself too.

Best wishes with your fathers recovery!