Mark,
Since your post was so honest and sincere, I thought I would treat you with the same respect and give you an honest and sincere reply.
As I read through your post I couldn't help but think this would be better suited for the "Sexual Identity Issues" area however I think your method for posting in the spirituality forum was driven mostly out of the types of responses you're seeking, and the thought that this was probably moreso within your comfort zone to post in this area of the forum. Either way, you've opened up alot with this post and I think thats a great thing.
Personally, I am not qualified nor really in the spiritual mindset to offer you any form of educated perspective in terms of spirituality. So if I may, I would like to give you some thoughts that occurred to me as I read through your post. My reply isn't meant to hurt or offend anyone and especially you. I just think perhaps its something that needs to be said. To provide a fresh perspective

First of all, I think its fantastic that you were able to share the background of your relationship with your now-wife. Because of all this history, because of your 3 children, and because you still say you love your wife and children... I am going to say that the decisions you're wrestling with are not decisions that can be made in any form of haste. That being said, this probably doesn't seem like 'haste' to you as you've done so much reading and studying on the subject.
To me it sounds as though you are thinking you need to come to some form of peace with your sexual identity in order to remove yourself from this immense unhappiness that is expressed throughout your post as well as in several other spots on the boards lately.
Oftentimes people in times of duress, immense pressure, stress, and depression, land at fixations which they feel will help them through it. It is only after they set in motion the changes that they feel will resolve this issue and find they are still just as depressed and stuck as before, that they realize that wasn't the case.
To me it sounds as though your unhappiness is real, valid and very pronounced. However when speaking of your family, wife, 3 children... That to me doesn't sound as horrible as the big picture here. Dare I say a bit of a bright spot in your life -- (a white fur rug and red pillows?) If I might be one to suggest: perhaps it isn't your sexual identity that is your issue.
Let's face it Mark. The other day you managed to find a way to make pancakes depressing. Everything looks bleak and black to you right now. Your black room with black furniture was merely a reflection of what is going on inside you right now. A person in this kind of mental state should NOT be making life altering decisions without first exploring every possible option. I say this because you mentioned you don't want to be married now (a life altering decision undoubtedly so).
Is this a sexuality thing? It's possible. I suspect this to more exhaustion and depression speaking than anything.
Here's some perspective for ya... I was floored when you said "the church
I work for". I was trying to figure out how someone, as depressed as you allude to be, could possibly work for a church. It then occurred to me, perhaps that in itself is the 'lie' that you feel you're living? Perhaps that lie is that you are making appearances at church of being OK and still able to function at your position. Whereas here on the boards, you are hideously depressed. Those seem like two different worlds colliding within you and might just represent this lie of conflict which is keeping you in this state.
I say this under the assumption that the folks you work with/for have no idea of the scope/scale of your depression. Am I right? If not then scrap all that I've said.
So Mark, instead of deciding that your marriage was never supposed to happen, take some time to examine other areas of conflict within your life. Have you considered that its your job that isn't right? Could be that you need a change in another area as well... Time to change houses/neighbourhoods/states? You say something's gotta give. I have no doubt about that.
I am really going out on a limb and saying all of this to you. I don't have a lot of context to work with. I don't have the luxury of time to go review all of your other posts to become a quick study on your life. I'm making these suggestions based on the facts presented in this post and the parts about you that I can remember.
You were noticeably vague when talking about your sexual identity being in question. It could be something that terrifies you to write here. You say that you've studied more read more and prayed more and have a very different outlook on what it means to be gay. Yet you didn't divulge details on any of these discoveries of self. This self-research of yours is what is needed to obtain answers and as you stated at the bottom of your post you are not looking for any answers. That much is true and evident here.
I think I've lost sight of where I'm going with this reply. However I think I have said all that I originally set out to say to you. If you think I'm totally off base here Mark then just let me know.
I guess I just see someone who sounds ready to throw away his marriage and life as an act of desperation to end the misery he's in. Depression sucks Mark, I know it. I'm glad you opened yourself up enough to get some other thoughts and such. I wish you the best with your exploration of this. I can only hope what I've said here will help.
~Brian