I went swimming earlier and i noticed the tip of my penis was sore, i thought i was just my trunks irritating it but its been 6 or so hours and im still feeling tenderness down there. the soreness is only on my external urethra meatus and skin is red?

This sounds like minor irritation from contact with the fabric of your bathing trunks and probably nothing to worry about. Conceivably the irritation has set of symptoms of underlying inflammation, such as urethritis (e.g. chlamydia), if you are sexually active and at risk for STIs. See a doctor if the problem continues a few days or if you also develop penile discharge, a visible sore, etc.

Something irritated the area- could be the chlorine in the pool or something in the water. apply a little cortisone (OTC) cream to the area and after peeing it should be OK soon