I EPed for DD1 for a long, long time, because she stopped latching early on and I didn't know how to get her nursing again. In the beginning I pumped around 20 oz a day, but by the time we quit I had been up to more than 40. I'd say that 30, at this point, is TERRIFIC. I just froze the excess every day, dated and labeled, so that when we did quit, I had a big supply stored up to keep her going awhile longer.
EPing is hard. It's hard to maintain a pumping schedule AND live anything like an ordinary life, and if you skip pumps your supply will bottom out pretty quickly. The best pump in the world can't extract milk anywhere near as efficiently as a baby, and that also affects your supply. That's what happened to me. Are you actively working to get baby back on the breast?
A good lactation consultant can work wonders. I really wish I'd gotten DD1 to nurse again; I regretted it a lot later on.