OP I was in your position, weeping at night because I couldn't bear going through it again - baby attached to me for hours, never sleeping.
We used the advice of a Millpond trained HV - they also have a book - it did involve a bit of crying, but much less crying than was going on while he was up all night in our bed! We didn't have to leave the room - you stay and soothe them while not feeding. I also read No Cry Sleep Solution - it helped me mentally but wasn't practically quite so usuful.
One really helpful tip from NCSS - write down your aims and be clear what you hope to achieve - that really, really helped. So rather than think 'oh god I want sleep' - you can think right I want this baby to go 4 hours between feeds at night, and if they wake any other time, I will comfort any way but feeding - (rocking, cuddling, patting while they lay in the cot/ singing etc) - it does work honestly. and because you have set realistic aims, they are easier.
Yes your baby might cry and scream because they are used to the boob to settle them - but once they learn to fall asleep without it they will be much, much more contented, I promise you.
Within a few days we saw a result - no, it wasnt that thing 'oh a few hours of crying then he slept through' but he did sleep longer chunks and we completely stopped bringing him into our bed - if he needed us, we took turns sleeping on his floor next to the cot.
He was sleeping better, he was calmer, - I stopped BF at night at about 9 months? It was much easier than I expected and he started sleeping through at that point...not always, but frequently....
The important thing to remember is that it is okay to want to sleep. You matter too. And your baby can get love and reassurance from you without feeding all night long.