My time

[EvenOlderButWiser]

I think you can both start out with the best of intentions, and trying to do the right thing for the children, but the reality is that today you are a different person. I know as I was in exactly the same situation that your in (two kids, married 13 years before I came out)
The reality is however that you will want to catch up on what you've missed out on all these years, which by the way is a completely natural thing to do. Your wife will also go through a phase of starting to resent you, which could get pretty ugly, especially if you have kids around (you don't mention their ages - and that also is a factor)
All of this external pressure can and will lead to emotional turmoil.

Before I came out I knew there was going to be a couple of steps to the whole process:

1. Come out to yourself - Can be really hard to do if you are in an otherwise loving relationship.
2. Come out to your wife - Very emotional for both
3. Explain to the kids, as much or as little depending on their ages (mine were 9 & 11 at the time)
4. Come out to both sets of parents - they will know something is going on and want some clarification of the situation
4. Move out the family home and give your self the space you need to develop and be who you are

It took me 6 months to get from 1 to 4, and another 12 months before my ex and I were on friendly enough terms to talk about the experience without getting over emotional.

Divorce followed some 2 years later when I met my bf, and we considered a civil partnership (which hasn't happened btw) Ive been with my partner almost 8 years now.

I guess the message is, everyone does things differently and don't be in a rush to do everything in the first month. Just take things at a pace that you can cope with emotionally, while still providing an appropriate level of support to the family along the way.

In the meantime, welcome to the rest of your life