Your daughter is in the last year of school so come summer you can insist on the sale of the house. So start planning. Your wife wants her cake and to eat it too - if she doesn’t want a relationship with you, she can’t equally decide that you can’t leave. If she didn’t want disruption for her child, she should have found a way to work on the marriage - she wants out, which is her right, but part of that for you both is supporting your nearly adult child to come to terms with that.
You need to start seeing the house sale, and any consequent disruption as the result of your wife’s decision, any financial hardship she might experience is a result of her decision. She should have been thinking through how she’ll cope on her own, not planning to keep you trapped in a loveless situation.
She doesn’t seem to have done that - so you need to. It’s ok to be heartbroken, but dear God take some ownership of your life, and give her back ownership of her own life and decision making. Start separating - physically (separate rooms, someone on the sofa, whatever), separate chores, etc. Start separating financially - look at what you’d be due to give in child maintenance and negotiate from there, look at the equity in the house and whether one could buy the other out. Get some distance, if you really can’t move out just now then start saving but in the meantime get out of the house even just for a night. Give yourself space from her and see how you feel.
You’ve let it drift for too long, judge yourself for that if it helps (it never does), then look to see what else is there - maybe some self respect? Maybe some optimism about what might be next for you - if the marriage has lacked intimacy for so long, it can’t have been truly fulfilling for you either, in the long run this may prove to be a gift to you, though it doesn’t feel that way now.
I’m on the other side, the wife that has just ended things in not dissimilar circumstances, it’s hard for us both in different ways, but I know beyond any shadow of doubt we’ll ultimately be happier apart.