Welcome to the forum!
Thank you for having the courage to post. It sounds like you have been deeply unhappy and unable to move forward, since your wife left. It is crucial that you seek professional help, as you need emotional support, and are also likely to be suffering from depression. Your regular doctor (GP) is a good place to start. Make an appointment, and explain your situation since your wife left. You will probably be offered a referral to a psychologist or counsellor.
If you need to talk to someone right now or when you are struggling at night, for example, call beyond blue's helpline on 1300 22 4636.
I'm glad you've come to the forum. It would be great to hear back from you!