How does this work??

My baby girl is 18 weeks, we follow her ww of 90-120 mins, and watch her cues for red eyebrows or yawning to start settling down for a nap. We have struggled to get her to fall asleep when trying the “drowsy but awake” advice so we have rocked her to sleep for all her naps/bedtime. We recently started trying to do some gentle sleep training. I’ve been laying her down asleep, and once she wakes and starts fusing or crying I have been setting a timer for 2, 4, and 6 mins and soothing each time until calm and heavy eyelids/blinking again…. The thing is, each time I go into soothe and then leave again, she is even more upset that I’m leaving, she’s almost hyperventilating and crying so hard, it’s impossible to see how this could ever start working? Can anyone give me advice, do I keep trying? It’s so hard to hear her like this and I feel like it’s not helping. I usually end up picking her up after the 6 mins mark and rocking back to sleep and holding her for the rest of her nap so she doesn’t get overtired. In regards to her bedtime routine, we do bath, lotion, owlet, book, bottle and rock to sleep and transfer to the Snoo between 7:30-8 (fyi motion is off, she is unswaddled and in regular sleep sack now). She always has a false start with this. She wakes after about 30 mins and falls asleep again around 9-10 pm.

Help, I feel like I’m doing this all wrong 🥴