Garlic, Option 3 is where I'm at, right now, for the last two and a bit years. Before you extol the virtues (with a cheeky little smilie) of enforced celibacy, perhaps try it.
Try going to bed with the person you love in the full knowledge that if you try to initiate some intimate contact you'll be rejected.
Try laying there, with memories of her hands wandering, making you feel special, then realise it's not going to happen tonight. Just like it didn't happen last night, or the night/month/year/2 years before. And it won't happen tomorrow. Or, possibly, ever again.
Try a nice meal, a weekend away, a romantic gesture, a decade of support for the lifestyle she's wanted, and still be the loneliest you've ever been. Depression, loneliness, the longing to be touched again, think where your mind might take you.
Then think about calling it a day, seek a new life. Think of what you'll lose.
A daughter who you put to bed six nights out of seven. Who you winded after all those overnight feeds when she was breastfeeding, and bottle fed when she moved on. All those bedtime stories, and more lately, since she's older, those bedtime chats as you tuck her in.
Then imagine that everyday, full life with your little one reduced to every other weekend, because that's what the solicitor says, because you've worked full time to raise a family, while DW works part time. She's took the employment risks you couldn't in the early years, and can now earn more pt than you do ft. Because employers understand a woman's need to tailor hours around a school run, so she'll get custody.
Then think "where the fuck so I go now".
Sorry to thread hijack, but the idea of put up with it or divorce so often advised on here is rather depressing.