You're in the "why" stage of this and trying to find a reason so it "makes sense." One of the best ways to look at life in general is that many times we never get to know the "why" something happened. With that in mind, focus on you and your future. Invest in yourself and in healing. Give to those in need and find someone who will encourage you and give you the same energy as a reflection of who you are. Good luck!

"He doesn't seem to have that value" yet you continue to foster that lack of values by not teaching him otherwise. Do you find a parasite to be a healthy long term play??

What do you believe? If we are simply judging off of what you told us, your overthinking and insecurities made you believe he was cheating too. Take a minute to reflect on the totality of your relationship. Otherwise, how could we randos know what your fiance really wants?

First, I'm sorry for this loss and for the pain you are going through. I wish you healing and restoration.

Second, IMO I would want to know. The first letter of FWB stands for "Friend"...