It's possible that a trial separation might give you both the space to breathe and find the right words to say. The marriage doesn't necessarily have to end (especially for insurance purposes here), but you might want to start considering whether the relationship has simply run its course.
Fostering a strong partnership based on helping your daughter navigate healthily and happily through life might benefit you more than trying to keep propping up an unhappy marriage.
Also, some couples find new ways to communicate or relate to each other again after dealing with certain issues. There's not necessarily anything stopping you from resuming the relationship later (obviously I don't know you or whether there are barriers other than the ones mentioned) when things have potentially become less strained.