Very red inflamed skin w endless acne cysts for 15 yrs. sometimes 20+ cysts in face at once.finally clearing. could this be from bigger health issues?

Yes: Acne and acne type rashes can because by many systemic illnesses and other problems most the time acne is isolated issue

See a dermatologist: Your acne is hormonal. Do you have normal menstrual cycles? Birth control? Some birth control makes acne better, some make it worse. Spironolactone at 100mg a day is probably where you should be. If not responding after a few months, isotretinoin orally for 20 weeks will rescue you. No acne pills should be used if you are pregnant.