Fuzzy white stuff is not common. Usually it is caused by watering issues.

Where do you live?
When did you seed?
What is your watering regimen - how often and for how long?

I'm in st Louis, mo. it was unusually cool when I planted a month ago & now it's in the mid to high 90's.i water lightly in the morning & again in the evening. the grass blades are still fine, not heavy. the clover seems to be doing better.

It's time to back way off on the frequency. Eventually you want to be watering once every 3 weeks for you in St Louis. You are watering way too often.

Start by watering only once every other day in the morning. Watch the grass. If the grass looks good after 2 days, go for a 3rd day. Don't get distracted by the soil getting dry. All you need to care about is the grass.

The amount of water you apply is important. Set out some cat food or tuna cans and turn on your sprinkler. Time how long it takes to fill all the cans. It will be from 20 minutes to 8 hours depending on your system and water pressure. That time will be your permanent time for watering. Memorize it. The day you do that test is day 1 on your watering calendar. Now watch the grass carefully for wilting. It should go many days. If it only goes less than a week, water right away for half your permanent time. As soon as it goes for a week, then the next time you water will be for the full time. The idea is to get the water to penetrate deep into the soil and then allow the roots of the grass to grow deep into the soil. Once you get into this program, you'll see the grass looking much better for much longer, no disease issues, and much less weed pressure. You'll also notice the soil gets very dry and even hard before you water again. That is normal. As long as the grass looks good, the soil can get as hard as it wants to.

Just stopping the frequent watering should stop the disease you have. If it does not, then write back.

I cut back on the water & now even more is dying. I wonder if I should try a blend of seed instead of straight fescue?