I had worked so hard planting grass this year and it’s almost all dead.

What kind of grass did you seed? I would assume tall fescue? Seeding of cool season grasses should be done in the fall.

Where are you located?

Yes it was fescue. I seeded in April. I’m just trying to stop this fungus so I can have healthy ground before I redo everything in the fall. We are in Tennessee

Seeding fescue in TN in April is a recipe for disaster, as you're finding out. Cool season grasses should be seeded in the fall so they have time to mature . Even mature fescue has a very hard time making it through summer in the transition zone, let alone month old grass.

Fungus is not a sign of unhealthy soil, it's a normal part of nature. You cannot kill the fungus in the soil with fungicide, actually fungicide just inhibits growth and protects the grass. It's something you live with.

So at this point, either you're watering frequently to keep it alive - which leads to major fungus problems, or it's dying due to shallow roots and insufficient water. My advice would be to let it go and save yourself the expense. Once weeds start to come in, you can do a couple applications of Roundup to kill them all and give yourself a clean slate for this fall. You should actually encourage weed seed to germinate right now by watering daily so you can then later kill them. If they don't germinate now, they'll germinate in your renovation and be much harder to selectively remove.

Once you do get a lawn properly established, you will want to rotate Scotts DiseaseEx and Bayer Fungus Control every 2 weeks through summer. Fungus control is just going to be a normal part of lawn care for you every summer, particularly since you're in in TN.