Hi Tegan,
I'm adding my voice to the chorus here. First, let me underscore, this is not your fault, you did not plan this.
Some couples survive transition, but that is less common. While I don't think for a second that you should resign yourself to the notion that your marriage is terminal, you should entertain that outcome as being probable. I have been out to my wife for over a year, and while we are still living in the same house, it would be inaccurate to say that we are together. We still do some things together, concerts, dinners, that sort of thing, but there isn't any physical contact. Yes, I sometimes have a fear of being alone, but I would have to say that the friendships I have forged here really take the edge off. You have a great advantage in that area, as you are geographically positioned to actually meet some of us face to face. You are not alone.
If it happens that you and your wife must part, that, as painful as that would be, is not the end. You are young, and (as I recall from your early posted selfies) quite good looking. You are intelligent. You are thoughtful. You are creative.
Teg, if the situation arises, you will overcome the fear and the ensuing emptiness, because you have options and you have friends.
I would echo Norma Lynne's advice here, take it slow. It's not a race. Keep in mind Suzi's observations: you can't control her and, you will get through this. As Julie succinctly put it: do not waste today in fear.
I hope this helps, sweetheart.
hugs,
-ellie