Canning failure

Ok, so I failed in canning last weekend.
It wasn't the canning part, it was the tomato sauce that I was making.
So, I get 25 lbs of tomatoes.
I lay them out all nice.
I chop 4 huge onions and end up crying profusely because they were really pungent.
I blanch, peel and chop every single one of them.
I puree them and put them in a pot with the onions and a dozen other spices.
Then I turn the burner on with the intention of letting it simmer for 1-2 hours.
Well, I turned the burner on too high, then walked away, and burned the hell out of it.
I figured I could salvage what was not burned to the bottom of the pan, so I transfer it to a new pot, put it in the fridge overnight (cuz it's like 11pm at this point) and go to bed.
In the morning, I put it back on the stove to heat because it has to be hot when you can it.
I turn the burner on lower, and walk away.
And burn the hell out of it again.
Needless to say, I felt pretty lame.
So this weekend, the fiancé and I are going to get like 75 lbs of tomatoes, and make tomato sauce and can it along with just plan tomatoes.
This time, I hope to actually make it to the canning part.
I'll just try to think of last weekend as practice :)
And, here's a very appropriate comic for our current canning obsession, enjoy.
http://pbfcomics.com/?cid=PBF226-Preserves.jpg#211