The left half of my left eyeball has become increasingly bloodshot and achy like its bruised in the last 24 hours. 25 years old, first time...?

RED EYE=get seen. A 'painful red eye' can be an infection (conjuctivitis), a corneal abrasion or a diagnosis more serious : iritis or acute glaucoma so a prompt doctor visit is recommended.
Possible hemorrhage. If you have a seepage from a vein on the surface of the eye, it will cause the spread of bright red blood over the whites of the eye. This is usually painless but there is sometimes some sensation. If the vision is not affected, and there is no significant pain, you can wait a few days to see if it spreads, if there are symptoms you can't explain then see your ophthalmologist.