I too was very good friends with W. A lot of our R was built on us just liking to hang out together. So losing the friendship was also something I feared.
I also thought it was a positive that my W was also friendly with me.
Sometimes it may be.
But for me, it took some beatings and luckily some wise people on this board to make me realize that her 'nice' was just that. It was not connected with her actually moving any closer to out M.
It also kept me in a funk. Because I was always looking at her. What she was doing. Saying. Etc. Putting your happiness in the hands of a WAW I found, is not a good thing
You have acknowledged your issues of depression. That is a great first step. Should be priority #1 at this point.
If your not thinking with a clear head, you're destined to continue to make the same mistakes.
BITS
Happiness is not something ready made. It comes from your own actions.