I'm so sorry, Annie. :huggy:
I think sometimes you just know and other times it takes a lot for you to know. In my case, I was patient (to the point of stupidity) because of "the kids." I tolerated/put up with/went to counseling for a YEAR, all the while knowing the GF wasn't going anywhere anytime soon. Finally, the straw that broke the camel's back was I had planned a trip to the east coast to visit my family. 2 weeks on the beach. ExH said he couldn't leave his GF (not in so many words :giggles

for that long so I said, "OK, then you can spend the two weeks packing your **** & moving out. You have until x date. If you're here when I get back, it's going to get bloody." He left & it's seriously been rainbows & puppy dogs ever since. My life is 10,000x better. Less $$, but better in every regard.
DH, on the other hand, didn't have to be told twice his ex was having an affair- he filed immediately, it was the out he'd been looking for for 15 years. WHY would ANYONE want to live that way?!
That being said, you didn't say what the trust is that has been broken time & again. You don't have to answer, but is it other women? Money? Drinking? Drugs? There is a difference, I think. Some things can be fixed with counseling & time. Other things, I think, just can't be fixed. Only you can evaluate that & decide. I can handle a lot, but will not tolerate anything that will ruin us financially for life. Clearly I can handle a GF. :lol: Handle, yes. Tolerate, no.
Also, your kids are young. Really young. I'm not saying stay for the kids, but do look at if your issues are compounded because of their ages. You guys work FT, have three little kids, must be running ragged with them all over town. That plus work, the house, their schedules, school, etc.... it's A LOT. And that can take a toll on any marriage. So, is it more that you guys just aren't a "couple" any more or is it beyond that?
(These are all rhetorical questions.)
On the other hand, if you just. hate. him., you probably know it's time to make a change.