Need help from a screen printing expert

I got a screen printing set up a while back, did some prints, and then didn't do anything for probably about a year. When I came back to start printing again, my emulsion was all goopey and chunky. I figured it was fucked anyway, and I might as well try adding water to it. I stirred it with water until it was back to the consistency that it started at.

I've now been trying to perfect a very high detail print and am running into a lot of problems. I remember from before that after I exposed the screen, I could clearly see the outline of the image before washout. Now, whether I expose for 10 minutes or 3, there is no outline at all. The emulsion is very difficult to wash out, and requires very high pressure water for a long time. As soon as I start to get the image to wash out, the entire screen blows out because I have to blast it with water so hard to get anywhere at all.

So, can anybody give me any insight as to what I'm doing wrong, or if adding water to the emulsion is what is causing this?

My negative is very dark, so that's not the problem. I haven't tried exposing for more than 10 minutes because it seems to be overexposed to me, thus no outline and very difficult to wash out. The shortest exposure time i've tried is 3 minutes, and I got the same results. I seem to remember from my prints before that I was exposing for around 17 minutes, so going shorter than 3 seems ridiculous.

Thanks, +K