due to my apparent snoring and her Menopausal night sweats and erratic sleep pattern.
If you snore, you snore. You have omly said its been shite for 8 years, and shes been menopausal with mood swings for 7 years, and had an affair.
Had you agreed to keep trying at your marriage after the affair? Or does she not know that you know.
Either way stop with the 'Im avoiding her', and not spoken for last 4 days.
Your both adults behave like it and tell her now.
Tell her straight, and stick to it. Neither of you is going to suffer any financial hardships as a result of the split.
Do this as amicably as you can manage, nasty exhanges or silences are not going to improve things for either of you.
Tell her, she surely won't be surprised and it sounds like the family home should easily be large enough for you to each have rooms for living and sleeping without having to bump into each other unnecessarily.
Both have your space and try to do this civilly. You are the couple that vowed undying love to each other at one point, tontry to treat each other fairly.
She has destroyed your marriage and trust by cheating, but you dont sound emotional or unhappy at the inevitable, so I'm not entirely sure what you are looking for here.
Follow up your words with action, i.e. i'll be writing/speaking with lawyer next week, to get the divorce underway and do it. They might be painful truths but at least its the truth.