A 32-year-old man presents to his general practice clinic complaining of a persistent, severe gritty sensation and pain in his right eye, accompanied by noticeable eyelid swelling and sensitivity to light, developing over the past 36 hours. He reports having difficulty seeing clearly with the affected eye since this morning. He is an avid swimmer and regularly uses soft contact lenses, often extending their wear beyond recommended periods. On examination, there is marked circumcorneal injection and moderate right upper eyelid edema. Visual acuity in the right eye is 6/15, while the left eye is 6/6. Slit-lamp examination, with fluorescein staining, reveals a central 7-mm corneal epithelial defect with significant underlying stromal infiltration. A small hypopyon is also noted in the anterior chamber. Lab results show a White Blood Cell Count of 12.5 x 10^9/L and a C-reactive Protein of 15 mg/L. What is the most likely diagnosis and the appropriate initial management strategy for this patient?