Hello group,
I am 1 hour north of New York City.
This year, my lawn has become overrun with crabgrass and other nasty
weeds. There are areas that are mostly weed, and areas that are mostly
grass(bluegrass/rye). This has not occurred in the 7 years I have been
here. Anyway, I would like to take some action now if possible. I have
a 100x100ft lot with my home on it.

1) Is there any fertilizer combo weed killer that I can put down on the
entire lawn now?
2) Can I also seed most of the lawn in combination with 1) now?

I guess what I am asking is that is there an alternative to killing all
the weeds with straight weed killer, waiting for them to die off, then
seeding and fertilizing? Most of the lawn care plans I see state to
ferilize/seed now, and apply weedkiller/fertilizer in the spring. But I
do not want to fertilize the weeds now!