I need some help. I'm really worried because my milk supply has dropped in my left breast. I…

I need some help. I'm really worried because my milk supply has dropped in my left breast. I normally get 2-3 oz but for the past couple days I've been barely getting 2 oz. it's also been really sore on my left breast as well. I've been massaging it while I pump to help just in case it's a clogged duct but nothing seems to be working. Does anyone have any ideas on what I should do? My right breast is still making the same amount it normally does.