It sounds like you could be experiencing balanitis, inflammation of the foreskin of the penis, often caused by irritation or a yeast infection. Symptoms may include white pimples, swelling, and itchiness. Keeping the area clean and dry, avoiding irritants, and using over-the-counter antifungal cream can help relieve symptoms. However, if symptoms persist or worsen, it's crucial to seek immediate advice from a dermatologist for detailed assessment and medical treatment.