It is physically impossible for the condom to be inside your penis.
Any prolonged pain and discomfort may warrant a doctor visit but it won't be related to this scenario.
You put on a condom for oral sex that you never had? But you left it on and when flaccid in your pants it came off? No, the condom didn't go inside your penis. That would be impossible. The pain you feel may be mentally induced from anxiety. Otherwise, ask your doctor about it. But the condom probably came up and off and shriveled and fell and you lost it somewhere along the way. Check the inside of your washing machine, for example. But this is not anything at all to do with the impossible scenario of your penis absorbing your condom.