@Roberts-USN,
I wouldn't talk about feeling excluded and miserable and cheated upon unless you do manage to reconnect. Don't do it
in order to reconnect. They won't believe you if you haven't first and foremost rebuilt some level of trust.
Maybe you can tell your daughters, or just
one of them for a start, that you want to spend some time with her and her family, and if they're okay with it, you'll try to organize something, like a weekend or a week together in some nice place, e.g. some place she always wanted to go to. The point of going away is to
change the context and avoid the presence of your ex, in order to start on new bases. And you can even have your new family join this weekend/trip/vacation, so that your daughter(s) can see how your new family treats you. You daughter might come out of a sense of duty, or curiosity, or guilt... That doesn't matter. What matters is that she come, and what you make of that time together. You'll probably have just one try. Don't overplay your hand, don't be apologetic or tense, don't shout, just try and make sure everybody has a good time, including your son-in-law and grand-kids. If it works, you can try it again next year, with two daughters, or another one this time...
It will in any case take a lot of time to repair your relationship with your daughters, and it may work with one and not another. You got to set your expectations low, and work on it progressively.