Paano Tigilan Ang Breast Pumping?

I started breast pumping earlier than usual. Di ko po alam na dapat 6weeks pataas bago magpump. 3weeks palang now si baby ko. Nag breastfeeding pa din po ako pero di pa kaya ni baby maubos milk ko. I think now naoversupply na po ako sa milk, kada pump 5-6oz na and I pump 3-4x a day. Pero I'm afraid to stop pumping kasi may nabasa akong pag di naempty yung milk sa breast, naninigas at namamaga, it may cause mastitis. Baka po may alam kayong ways or tips? I want to breastfeed my baby until 1year manlang. Thanks sa sasagot. ?