Another paint question., my supplier has given me horrible info Options

[VaccaRabite]

So, granted tonight I am starting in a bad mood. My day started sucking shortly after waking up this morning, and I have been looking forward to being able to work on the car tonight to work out my frustrations.

So, it turns out that my paint supplier has given me all sorts of bad information, which I used - and explains why I was having such poor performance with my paint.

So, details.

I am using a Nason Ful-Thane 2K Urethane paint.
Under that is Nason Select Prime 421-17 2K Urethane Primer
and under that is Full Poxy 491-16

What I did not put down, between the 2K Primer and the top coat is a sealer, which I just noticed is marked REQUIRED on the data sheet I just printed out.

So, what. Am I up sh*ts creek? What does this sealer do? I am just finishing up color sanding now. Do I need to strip it back down to primer, get more paint mixed and start over? If I do, I don't see how this car is going to get done this year.

My jobber also told me to use 800 grit paper, and then polish.
Opps, they were wrong here too. Way wrong.

Can this be saved without stripping it again and spending another boatload of money on more paint? Or did my bad day just tip the scales into horrible?

Zach