Is there a reason you do not block HER on Facebook?
This is not about winning and losing. It's about healing.
You can choose to do that, you know. You can make choices that support it. But you're hung up on "not letting her win." If it really were about winning, she'd be ahead right now, because you've given her such enormous power. You won't make healthy decisions for yourself, lest she "win." Do you see the perversity of this?
I don't know that moving is necessary (it might be). I do think that you and your husband may have to move on from the school. I suspect that some point, you are going to realize that your plan to return to "your" school will not work if she is there. You will realize that she is not leaving---and has NO obligation to do so. That she is no more responsible for the affair than your husband, and she has no less right to be there. You will realize that your husband's job at "your" school, though once thought to be ideal, threatens to end your marriage as surely as the affair did. You will see that ongoing contact with this woman, in any way, shape, or form, is toxic to you and your marriage----and far, far, FAR outweighs any benefit of continued employment, for either of you, in a particular school.
Further, I think this realization is going to be shocking to you, and wish that you would see the likelihood of it occurring and PLAN for it. Because I suspect it will really knock the wind out of you, and happen in a way that you feel the need to make abrupt changes---when, in fact, you could be utilizing your leave to make wise decisions for your future, and starting to build that future, with your husband.
I know, though, that you have to do this at your own pace. Sadly, going your own pace may result in significantly more injury to you---and to your marriage. I know this because I refused to confront the truth, too. I very much wanted it to be different--and was determined that it would be. I was wrong. I think you may be, too.
The job is not what you wish it were. It is not the place you want it to be. It may reflect part of your vision, but it is where your husband's affair was nurtured, and where it grew, where it thrived. It is an environment that continues to welcome and nurture OW. An environment where YOU and your HUSBAND will be expected to work constructively with her. That you are intent on your husband remaining there with OW and insistent upon returning there yourself is perplexing. It is no wonder your mind is not clear, and that you are battling severe anxiety and depression. Your dreams and reality are clashing, and you don't want to believe what is real and true.
I'm sorry for your pain---but know from hard experience that you have the ability to remove yourself from some of the things causing your pain. You are valuing a SCHOOL over your well-being and that of your marriage. You are valuing pain over healing.
She is playing no more games than you are. You're playing them with her. You're playing them with people at the school, with whom you are not being honest. But worst of all, you're playing them with yourself. Somehow, this makes a day-long Facebook blocking seem...as insignificant as it is.
For those SIers who are Christian, I'd value your prayer too.
The prayer request is not offensive, and does not require a warning. That is is extended to only a portion of the community, and the implication that the prayers of others are unwelcome, is and does.