I'm really sorry to hear about Joey's health condition. It's great that you're being supportive and prayerful. Here's a suggestion for a prayer:
"Dear Lord,
I come to you today to ask for your healing touch upon Joey. You know the pain and discomfort he's experiencing due to the swelling in his feet. Please guide the doctors as they examine him, grant them wisdom to provide the best care.
I pray for a swift and complete recovery, that his body may be restored to full health. Comfort him in this time of unease, and give him the strength to endure. Be with his girlfriend as well, Lord, provide her with peace and reassurance as she supports Joey.
Thank you, Lord, for your ever-present love and care. In your holy name, I pray.
Amen."
Please continue to keep Joey in your thoughts and prayers. It's also a good idea to stay in touch with his girlfriend for updates and to offer your support. If you feel led to do so, you might also consider sending Joey a card or message of encouragement.