I could have written your post op, dd was and to some extent still is a rubbish sleeper. But like you when she reached 14 months I needed more sleep. After thinking we cracked her sleep at 11 months illness on all our parts meant she was taking several hours to settle and feeding almost constantly through the night. So it was my new years resolution was to stop night feeds.
For us it meant less sleep before we got more. Dh works evenings so bedtime mean I'm on my own. Sleep for dd was bf and me. From new years day I fed her until she lost intrest/ got sleepy then put on several layers and lay in bed with her with my eyes closed until she fell asleep.
For night wakings I told her that the breast was asleep, that she should go to sleep too and that it needed sleep to make milk for the morning. Then that she could have a drink of water and a mummy cuddle. Chatting reassured her and she'd eventually go back to sleep with less crying than I'd expected. She'd also cuddled into dh if I said no. Her morning feed was allowed when dh went to work, so I told myself and her milk was for when daddy got up. After 4 weeks her she woke once or twice and settled back to sleep quickly without feeding.
The big difference for settling her to sleep came with converting her cot bed into a toddler bed. She has a feed in her bed, story, teeth brushing, night light on, song, kiss good night and tucked up. I'm very gradually retreating. I sat next to her holding her hand, then hand on her pillow, then the edge of her bed, then sitting at the bottom of her bed. Two months on I sit in the doorway and wait for her to fall asleep. We had her bed pushed against the side of ours to begin with. Now she starts of away from us and we move her bed when she wakes.
So sleep's still not ideal, but is getting better and we've been able to do it gently. The plan is to slowly get her into her own room.
The things that really helped when we started this change was dh being able to take over in the days so I could sleep in preparation for the night. Having dd between us in the bed. And making sure she got a good day time sleep at the cost of almost everything else.
Good luck op.