Oh mama I am so sorry! I know how you feel. My knuckles were cracked and bleeding because of my cold. If you have had cold sores in the past though shouldn't Denver at least have your antibodies for that? I know it can be pretty serious for little babies to pick that up but thought they had some immunity assuming you had exposure in the past.
Stay positive. This too shall pass. And you will be covering him with kisses again soon I'm sure!