As your post seems to indicate, you're scared shitless right now and it seems like the entire world is coming to an end. Trust me, even if it really seems that way, it's not.
For now, grit your teeth and go through the bad stuff. Tell your wife. Be honest with her. No matter what, she's your wife for a reason- she'll support you through all of this. If you neglected your relationship with her a bit because of the startup thing, then she comes first now. Then tell your investors. Tell your employees. Tell whoever else you need to tell. Be honest, genuine and straightforward. The next few weeks are going to suck big time, but you'll get through them.
Once the big stuff is behind you, take a few weeks to breathe, if possible financially. You're coming to the end of a long, arduous journey, and that's always something hard to process. Try to find joy in the little things that you didn't have the time for during your founder mode. Have brunch with your wife. Go take a walk alone in the forest. Read a book. Take time to recover.
You will find another job. You don't realize this right now, but having run a startup for 2 years gives you more skills and experience than others have developed in a lifetime. If you have to take a job right away because of financial hardships, take something low stress (consulting/freelance could be a good choice, for the flexibility, although it can be hard to get started with no leads). Now is probably a bad time to do another startup. Also, you probably want to use this as a lesson to remember that you should always have ~6 months of expenditures in the bank that you NEVER touch precisely for situations like this one.
Don't worry about the investors. It's part of their job - you're not the first startup that they funded that failed, and you're not the last either. Be professional with them- if you want to do a startup again in the future they will remember your honesty and ethics more than the fact that your startup failed.
You ran a startup for 2 years. Solely by doing that, you've gone further on the path of entrepreneurship than 99.999% of people who call themselves "entrepreneurs" have. Take time to grieve, but also take time to see all that you have accomplished.
If you still feel depressed after a month or two, go talk to a professional therapist/psychiatrist. Sometimes we need a little external help.
It's going to be OK. :)