Ferber method — I’m ready, I think…(SOS)

I tried Ferber method at 6 months — baby threw up after the longest interval, I had a panic attack, felt like a horrible mother and decided never to sleep train again.

Here I am 6 months later, over a year sleep deprived and I think if I have to do this again for another year I might be dead by the time LO is 2 yeRs old.

Here is the lowdown—

1. Have been co-sleeping since 6 months. Drowsy but asleep never worked. She ALWAYS wakes up when I move her from bed to crib.

2. Baby breastfeeds only and still wakes up every 35 mins to 1 hour and 45 mins (max) 🥲 She falls back asleep 2-3 mins after connecting to my boob or being rocked.

3. She now has a few comforter toys which she didn’t have before.

Can someone break the ferber method down to me like I’m a child.

1. What do I do if my baby doesnt settle between intervals? Do I still leave?
2. How long do I do the ferber method for in one night?
3. Is 1 year old too late to start?
4. Has anyone done it with a 1 year old successfully? If not, what method worked.

Please help, I just want to sleep peacefully and deeply for one night.