“Yes, we do have fun and laugh together.
I just miss the closeness.”
The perfect is the enemy of the good. As you get older, the good ones tend to get caught in marriage and are taken, leaving you to choose among a group with a much higher percentage of the damaged. Dump the guy you have fun and laugh with, and what do you end up with? By and large the older you get, the more most of the good people find their way into a successful marriage, and the more the remaining people are single for a reason, and that reason is what you will have to choose among.
You could find a guy who will bang you for a month, and then go banging other people.
You could end up in an abusive relationship that you then have to extricate yourself from.
You could end up with the spendthrift, the angry guy, the coward, the selfish guy, the narcissist, the psychopath manipulator, and on and on. They are out there.
Marriages go bad, and people end up single late in life for lots of reasons. Few are as good as we had fun and laughed together, but we didn’t have sex as much as I wanted.
Having seen really bad marriages end, and what they spill onto the singles market at least on one side, and how the good ones for marriage quickly move on and get hitched, I think your question should be less on how could your marriage be better, and more on how much worse will you be off starting over.
Actually being alone for the rest of your life could be better than many of the other paths you will have before you. Get hitched to a narcissist, and you could end up wondering if he will put something in your food, or sabotage your car. And you won’t see it in the beginning.
Food for thought. If he has your back through medical problems, and is loyal, you can end up doing a lot worse.
And then there's the issue of the kids. Keep in mind that the father loves his kids. Any future step father is not likely to develop as big an emotional bond, especially as the kids are older. The father has an incentive to keep the marriage together for the sake of the kids, while any future step father does not.
Plus the kids WILL be angry at the parent who they perceive as being the one who decided to blow up the marriage.