Red pimple inside lower eyelid. looks like a stye but ive never had one so not sure. how can i treat it or prevent it from getting bigger? thank you

Stye: Probably a stye. Apply moist heat with a cloth and that should bring it to a head and discharge and then heal. Good Luck

Agree with Dr.F.: If it has lasted longer than a week or so, it may have become a chronic infection and may require intervention by an ophthalmologist. You may visit this site for chronic lesion. https://www.mayoclinic.org/diseases-conditions/blepharitis/multimedia/chalazion/img-20008560 Have a healthy diet, exercise 30 minutes/day, drink plenty of water, have safe sex, no tobacco alcohol weed or street drugs.