Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you today. I do apologize that your question was not answered before. Different experts come online at various times; I just came online, read about your situation, and wanted to help.
Again I do apologize that my colleagues could not aid you sooner. If you would still like assistance, can you tell me:
Is the swelling over the nose
or more involving the mouth?
Is the swelling hard, soft, fluidy, warm, or painful?
How much Benadryl and Amoxicillin
did you give? How often?
How much does he weigh?
Can you take a photo of this? If you can do so and post them online, this will let me see what you are seeing. To post them, you can either use the paper clip on the tool bar above your text box. Or if you cannot see that on your computer/phone, then you can post them on an alternative site (ie Flickr, Photobucket, imgur, etc) and paste the web link here for me to check.