Hello,
Well let me start off by saying I understand what your going through, and it gets better. My son was about the same age when we decided it was time to wean him off the bottle. To be honest I don't think that its crucial, b/c my mom said that my brother and I were about 2 when she finally got us off. However I'm sure your feel the pressure from the doctors like we did.
So here's what we did. We took our son's sippy cups and filled them with milk, b/c thats what he was used to drinking before bed. It's hard at first but as long as your consistent it will only take a couple of days. I kept telling my son that the bottle went bye bye to make some other little boy happy, it was all gone and he had to be a big boy now. He would say bye bye, and i said yes. However I never let him drink a bottle in his crib unsupervised but that was me.
We started a thing where we read to him every night and we have a sippy by our side, he takes sips from it periodically, but not even close to how much he used to suck on the bottle.We do still give him a bottle in the morning, but most of the time he doesn't want it. We're actually one step away from having him completely off the bottle. The transition has been very easy. Just stay consistent.
I hope this helps.