You are likely experiencing balanitis (inflammation of the foreskin) with temporary phimosis due to swelling. It is crucial not to self-medicate, as the wrong ointment can worsen the infection. Please see a doctor promptly. If confirmed to be bacterial, they may prescribe a prescription-strength topical antibiotic (such as mupirocin) or oral antibiotics. For now, gently rinse the area with warm water without forcing the foreskin back, and pat it dry. Avoid harsh soaps. If your foreskin is stuck behind the head of your penis and cannot be pulled forward, or if you cannot urinate, seek emergency medical care immediately.