I think you have gotten sound advice in this thread. You need to shock your pool up to about 15 and try and hold it there as Carl advised above. You also need add some Borax to bring your ph up above 7.0. I also don't understand how you had a stabilizer reading of 30-50 a couple of days ago and now you have none. That doesn't change that fast. At any rate, keep shocking and try not to let your cl level come down. Test several times a day and each time add enough bleach to bring it back up to shock level. Run your pump 24/7.