Clogged filter, cloudy water.

Hi,
I'm opening my pool for the 4th time. Never had a single problem till this year. The pool water was very green when i pulled the cover. I vacuumed it, & shocked it. The green disappeared, but now the water if very cloudy. I can barely make out the bottom (vinyl liner) in the shallow end. I took a sample to my local guy and added all the chemicals recommended. Water is still cloudy even after a 3rd shock.

Also, my DE filter keeps clogging quickly. I've backwashed and re-DE'd maybe 8 times now in 5 days. Last night, it clogged (25 psi) in about 5 hours. The water is "clean"... no debris, just cloudy water. The DE is light tan when I backwash. Only thing i can think is that the dead algea is what is making the water cloudy, and clogging the filter. My water test, among other things, said my cyanuric acid was low. Directions say to pour into skimmer and not backwash for a couple days... but i cant make it more than a few hours without hitting 25 psi. Out of frustration, i added it anyway (tried to pre-dissolve), but i think i wasted my money & time. One day after shocking, test kit says my free chlorine is almost zero. Thinking that this is a result of the low stabilizer. But i cant add the stabilizer cause the filter keeps clogging!!!!

Feels like I'm stuck in a vicious circle. Anyone have any advice?

Thanks in advance!
Tim