@SoapFTW
Feel for you bro, but I dare say quite a few blokes on here have been thru very similar circumstances. Most have come out the other side at least a bit happier, either thru separation or other means.
It's weird but since I started sugaring, my relationship with the wife has improved out of sight. Once you get what you are missing from your life elsewhere it is easier to overlook the shortcomings at home, and see your wife in a more positive light. I'm not sure if that is across the board but it is what happened for me.
However the fat shaming (and I'm sure I'm bigger than you) is not something I could live with. My wife sometimes mentions my weight, but it is more of a "you should lose some to be healthier" vibe.
If you can't afford the sugar bowl then why not try and get a FWB. The 2 I've had in the last 12 months like having a meal, and heading to a LH. Very light hearted, and just good fun. One is 25, the other is 37. Both are hot and have good banter.