He sounds like a workaholic but I think also lots of high-earning jobs come with the expectation that the person will work all the time and be accessible at all times of day. That's how you win the competition for those high-earning jobs.
I think an hour of help from your husband in the morning and two at night is actually quite good. I went through about a decade with my husband, when my children were younger, where they were lucky if they got 20 minutes a day of time with him. Even on the "best" holidays, he would maybe spend an hour or two per day with them (doing Disney things), and the rest of the time he would either be doing his own hobbies on his own, or he would be working on his laptop.
Everything is a lot better now (my dh in his 50s): he doesn't work as much because he is more secure in his career. He helps with the kids (teenagers) and house a LOT: cooks dinners, cleans the kitchen, we go on holidays together, etc. I think it is easier for him to spend time with them now because they are doing more adult-like activities that he enjoys. He still works a lot but not the same insane amount as when he was younger.
If it's possible, I would just take the kids for fun activities on weekends yourself. Don't wait for your husband. If you divorce, you'll be doing activities alone with the children anyway.
I think you have to find out whether your husband is truly committed to the marriage or whether he is just using you as a wife appliance until you stop being beautiful and he can find a younger model of wife appliance. I think the first thing you need to do is to protect yourself financially. Is he actually "hiding" his income from you, or is he just too work-focused to take time out to ensure you know where all the accounts are? Are the accounts, the house, in both of your names, or just his name? Do you have life insurance for him, of which you are the beneficiary, so that if something happens to him, you and the kids are taken care of? I wouldn't hold it against him that he doesn't get these financial chores done himself, but if he won't allow you sufficient access to get them done for him, then that's a red flag, IMHO. A forensic accountant might be useful to you, but do you have access to money that your husband doesn't control, so that you can hire one? If you don't, then you first need to solve that problem, before you can even make any moves to protect yourself and the kids financially.
If he's committed to you, but just a "garden variety" workaholic, then I think that is manageable. If he is not committed to you, but just going along until he no longer needs you, then that is a whole different level of problem. The fact he wishes to sleep in separate bedrooms signals the latter, IMHO, but you know your marriage best.