@allfree15 As someone who has tried to find "solutions" to sleep, just try to remind yourself that if it was that simple there wouldnt be such a huge market of sleep products, trainers, books etc etc.
Where I live there is a whole service provided of nurses that will help you with your babies sleep, its amazing but it still doesnt fix them. So many people I know have done it and it works a bit for some, not at all for others.
We worked for a month to get her to fall asleep in her crib, it worked maybe 60% of the time for a week. Then she learned to sit up, stand up and crawl all in the space of 10 days. It all went to shit as the second you put her down awake she would pop up and pull herself to standing. I lost my mind for a while and then just went back to holding her to sleep. Sometimes it helps to try other methods but other times the path of least resistance is best for your sanity.
Edit to add: anecdotally i stopped feeding to sleep mainly by focusing on feeds during the day. I fed her when she woke up and I think this helped to gradually associate feeding with wake ups. I also got her dad to do way more bed times after I knew she had a full belly, becaus he doesnt smell like milk so the association wasnt there.