Two things are usually at the root of chronic red eye in a 28 year old. The first is a condition called Episcleritis. It is a chronic inflammation of the clear skin on the white part of the eye. The most common irritant is UV light. So you see this condition a lot in guys that work outside, or in people that live at higher altitudes. Because it is inflammatory, you'll generally need a corticosteroid applied directly to the eye to knock back the symptoms. The safest ocular steroid out there now is a drop called Lotemax. This is the only one you'll want to use if this is a chronic problem cause other steroids have a much higher risk of glaucoma and cataracts. The stuff is $100 a bottle because the patent is still good and B & L is making a killing off it. Get your local eye doc to write you an Rx for it for now and use it twice a day.
The second most common cause is vasoconstrictor rebound. This means that any drop you've ever used to "get the red out" has now left you with a chronic dilation of the vessels on the eye. And any time you do use these drops, you're just making the chronic problem worse. There is nothing out there that will whiten your eyes in minutes like a vasoconstrictor, so quit looking. If you want them to get worse, keep using Visine, Murine or Clear Eyes. Even a lot of allergy eye drops have this crap in them.
Stop all whitening drops and get your Rx for Lotemax. Then try to taper off the Lotemax over time. I don't think your oral supp use had much to do with the redness though. JMHO