Hi TC.
I'm so sorry you feel so down, it must be awful longing for your wife.
I was going to say what Annamuller said, what would your wife want you to do?
Like you say, if you don't go, you'll be stuck in your flat, and the anxiety, and depression has won, you have to fight these things, and keep fighting.
You only have to go for 1/2 hour, maybe you could take something of your wife's with you, like a bracelet, or hanky in your pocket, so she's ‘there with you ‘ for support, and if you feel a little lost, just look at it and know you're not alone....if you see what I mean.
When I lost my mom & dad, I wore my dads gold chain, wore it for ages, it really gave me comfort.
You try n go girl, get out of that flat, even for 1/2 hour, just show your face, you never know, it may make a big difference...