I agree all affairs are unique, that is why infedelity forums can be useful to some and useless to others, who want to overcome betrayal.
In your situation op I can see why this has been so hard for you.
You say the om was in your social circle, that's hard because you must feel humiliated, especially as it could become gossip.
For women when they have affairs it brings into the equasion a man's virility, your wife placed you in a possition whereby society thinks one man should defend his honour against another.
These are feelings of inadequasy, not just in your marriage but to the outside world.
Unfair, but we women also have our outside appearances to keep up when we have been betrayed, (think not pretty, slim, young enough etc.)
Anyway there is so much for you to overcome, it will take a long time and will depend very much for you how your wife can re build your confidence. This confidence is wrapped up in the fact you don't believe her, not just about the details of the affair but about how she truly feels about you, you don't believe she cares, loves or finds you attractive anymore, this is the hurdle.
Unfortunately many people who have been betrayed, never regain their confidence and that is scary, you just don't know the future and how you will heal. Like @AccrossthePond states the healing is all on the betrayed.
The broken plate analagy is right but I would liken it to being shot in the foot by your partner more, you are there living with the person who shot you, they watch your pain and then try to tell you they didn't mean it.
They watch you hobble arround in pain and either look on with anger if you complain, or pity you if they are the type to try to help you overcome it.
That pity can be as painful as the dismisal and minimising some cheaters dole out and no one wants to be pitied especially by the person who wounded them.
Some victims overcome the pain with retribution, some take the hit and masochistically hobble on and others leave, which one is up to you.
After a year, you are still not there with your decision, maybe you never will be, you are frightened that you will be in this limbo forever, your wife did this and there are no real answers, I'm just sorry for you as you sound quite a reflective man.
The irony of it is, when couples split when one partner cannot overcome the betrayal, it quite often is the cheater who moves on much more easily, emotionally anyway.
Leading me to think, were the betrayed ever really loved in the way they should have been from the start.
They say we all have our lobster, maybe your lobster was not right, maybe you need someone with more integrity, a better moral compass, more empathy a better connection, all things which many people value but many others don't.
It's not weak to expect to be united with someone with similar values, you just have to get to the point where you start valuing yourself again op.
Hopefully that decision will become easier when your confidence returns, I hope it does because you sound lovely.