Alright!!! I admit it!!! I need help.

I have a 92' ES that up until about a month ago was running just fine. One day, I was driving along when it started hesitating and running like crap, it seemed to run worse(sounded like it was missing) when accelerating but it would stall when idling. It continued to start for the remainder of the day but with the aforementioned problems still occuring. The next day, I went out to start it and it would not, and has not since. I replaced the Fuel filter and Fuel pressure regulator but cannot figure out where to go from there. Any information or suggestions would be greatly appreciated. Could a faulty EGR cause these problems? How about the ECM, which was just replaced about 5 months ago? What would cause such a sudden onset of these problems? Thanks in advance for any help/suggestions.

Dan