I'm so so sorry for what you are going through. It sounds like you have been hit very hard with depression (understandably!), so first and foremost I hope you will seek treatment as it may help you get through the times ahead. I can completely relate to the shock of it all. I just got a loop ileo 5 weeks ago after a long, difficult battle with my pouch the past 2 years. I fought it for a long time and had to grieve, but did come around to accepting it and now feel so much better and healthy that I am actually glad I have it now. But, it took me a long time to get to a point mentally to be OK with it, and you are allowed to not be OK with it if that's what you need. You had thrust on you, so didn't have time to process it, nor a long period of illness that made you want relief. But, it also isn't written in stone yet. Your fistula may heal, you may get a second opinion about managing Chrohn's with a pouch, there are still a lot of options. It's hard but try to remember healthcare is a process rather than a start-finish game.
As for managing the ostomy, do you have a good stoma nurse? There are always products/ideas to get it to fit better, but you need someone good to help you. If not, have you called one of the supply companies (Coloplast, Hollister, etc.)? They have customer care specialists that you can go through your challenges with, and they will even mail you free samples of things to try. Sometimes you just need the right product and then at least the annoyance factor of leaks would be gone which might really help your perspective in dealing with everything. I had days where I cried changing my ostomy because the stupid thing would poo everywhere (like "god what have I gotten myself into!!") because i'm still learning how to manage it, but now I'm already starting to have days I forget I have an ostomy, and a month ago I never would have thought it possible. For your output, I'm sure you've tried a low residue diet/pasta etc. My stoma nurse told me to drink 1-2 G2's a day with high output, but to avoid artificial sweeteners and lots of sugar otherwise. Did you get to see a dietician in hospital to help you with diet? My ostomy put out a lot the first month but is behaving better now. Also, if they think you have Chrohns, do they think the high Ostomy output is related, like maybe there is some small bowel inflammation? Just a thought....I think there are people on this site with ostomies, so if you start a thread with the challenges you are having, you may get some good ideas.
I hope these thoughts help you, and you take time to grieve what you've gone through, these things are traumatizing to experience and it makes perfect sense to feel the way you do. Your wife and family likely understand completely why you are not able to be attentive right now and just want you to focus on taking care of yourself. Hang in there!