Bless your heart.

I'm so sorry this has happened -- but know that you are NOT alone. We're with you, if that means anything to you at this time.
My friend, you're going thru grief right now. You're grieving the loss of the marriage. And grief takes time. It's different for everyone -- some grieve faster, some slower. It's like a death -- the death of the marriage. And like death, there are 5 stages to grief: Shock, anger, depression. bargaining and acceptance. I doubt you'll go thru the bargaining since that's been taken care of by the legal system.

But the others, yes. I'd say right now, you're in the depression phase. I hope this doesn't last TOO long.
Even tho the divorce decree says you get the kids those particular times, after while you and ex-wife CAN negotiate more frequent visits IF you and ex wife keep your relationship on friendly terms.

If you two can stay friends, she WILL relent, hopefully and let you have the kids more often. I doubt she's an ogre and she should be able to see how much these kids MISS you. It might take a little time, after the kids start begging to see you -- and they probably will.

So continue to be the BEST dad you can be when you have them, and let things work themselves out. That divorce decree isn't written in stone.
And for your own sake, get some counseling. You've been hit hard by this, and this depression is taking it's toll. Some counseling WILL be of benefit to you if you can afford it, or if your insurance will pay for it. If you can't manage it, talk to your medical doctor -- he can help. There's no need to suffer like this. Believe me, I know.
God bless you my friend -- and keep posting cause it helps. We'll be here. Big hugs, Lee