I follow Sleep Well with Hannah, Parenting Community on Facebook. She is a sleep consultant who has recently held a whole free sleep workshop in Jan which I unfortunately think is closed now. There is a free sleep workshop in the community but it only gives a few pointers - however you can ask questions on there and will have literally thousands of people to help you!
Hannah's technique is to basically take very small steps, to do less to get your baby to sleep. Basically ever since we've had our babies, we have taught them how to get to sleep, be it feeding, rocking, co-sleeping etc. We now need to gently teach them a new way to get to sleep - and on their own eventually - but this takes time and patience and we can't just chuck them in the cot and hope for the best! She is not an advocate of cry it out methods, but this is NOT a no cry method - your baby will protest and cry at first at the changes, but this gets less and less every time. The difference is you will be there comforting and supporting your baby the whole time.
The first thing you need to do is take a small step away from the normal way you get your baby to sleep - your "safe space". The most important thing is that whatever you do, you MUST be consistent. Constantly changing what you're trying to do to get your baby to sleep is just confusing for them and then nothing works. So pick something you are comfortable doing.
For us, we fed to sleep on the rocking chair. So my first step was just rocking on the chair, patting and singing the same song (over and over again!). Then after 3-4 days, I stopped rocking and just did patting and singing (note these naps were contact naps still). Then time for the big move - patting and singing the same song but in her cot. The first time it took 30 mins and a lot of crying but she eventually drifted off...next day I tried it took 10 minutes! Always start with the first nap of the day and once that is going well, you can introduce other naps and then bed time. Soon I will stop patting and just sing. Then I will just sit by her cot, then move to the chair, then the door and eventually out the room! It will take time but is more gentle than cry it out. Some people take the step of moving from sitting to laying down and cuddling, then laying down and patting, then just laying down before moving to the cot. Key is to 1. Not take big steps 2. Be consistent and do the same thing every single time. 3. If you start getting stressed, leave them in a safe place, count slowly to 30 seconds, then straight back to technique if baby is crying more, but keep counting if baby is protesting less.
Sorry that was massive but it's really working for us! Hannah also has a sleep course you can pay for if you need more help /support but defo join the FB community first as you can get lots of free advice from other parents and from Hannah Love Costello on there. Good luck! Not easy but we are really seeing results!