Can you write a double list, one with the good things about her and your marriage and the other with the bad things about her and your marriage.
Think it over, don't rush it.

When you are pretty sure you are done, see where the scale goes.
If it goes on the bad part (as your post seems to imply) you've got to talk to her.
You'll find the better place and moment but you really got to talk to her before your dissatisfaction gets too strong.

Maybe there is still a way to save your marriage and your commitment, but you can't do it alone. You can only save your marriage with your wife

Best of luck