Are you seeing a therapist? How much support do you have from family and friends where you are?
It's not good for your son to be with a single parent who has depressive issues going on. What other kinds of "parenting" does he have in his life while you heal and adjust? How much Skype time does his mom give him? Or is she constantly either studying or playing with the bf?
As far as the poly bit, did either of you research how to actually handle polyamory, or just jumped in blind? It's time to play catch up, read about "opening up" on the morefortwo website, read the book Opening Up, etc.
Also, your wife mentions you feel romantic feelings for her bf now too? How does that fit in?
You didn't address my other questions or suggestions, you just sort of complained some more.
Think about what you can DO. This relationship aint gonna fix itself, buddy.
Love withers under constraint; its very essence is liberty. It is compatible neither with envy, jealousy or fear. It is there most pure, perfect and unlimited when its votaries live in confidence, equality and unreserve. -- Shelley
Mags (poly, F, 60) loving miss pixi (poly, F, 38) since January 2009, living together since 2013
also loving Punk (monogamish, former swinger, 42, M) since Oct 2015
"Master," (mono, 34), miss pixi's Dom for 2 years