Don't be so hard on yourself

It takes time to see an improvement and sometimes it is a two steps forward and one step back situation. My
DS has never slept through (not what you want to hear

) but he has made some huge improvements with the NCSS changes. He even tells me what comes next in the routine

There are days when we go backwards and we just start with the basics or go back to the *bad habit* in order for him to get to sleep because sleep deprivation makes it all soooooo much harder.
DD is difficult at the moment. She is having (roughly) 2 naps per day if they are decent or 3 if they are one hour ones. The afternoon is tough because she NEEDS a sleep around 5pm, otherwise she has been up for 4-5 hours by bedtime and that is far too long. She then gets overtired and it takes forever to get her to sleep and to stay asleep. I am also finding that she is waking after the first sleep cycle at night too so I have to go in to her before she wakes up to try to resettle her as she stirs, rather than have her up for another hour or two.
You are doing great. Allow yourself to make adjustments. Give yourself permission to change one little thing at a time rather than everything at once if you think that might help / make it easier to stick to / be less stressful.
With
DS, we decided to concentrate on getting the routine sorted before moving onto the other sleep issues and concentrate on his tired signs for setting a bedtime. Amazingly, this routine has also seen a big improvement in his sleeping too. Not every day (I wish!!) but much better than before. Because
DD is also in the same routine, she is now rubbing her eyes and is ready for sleep after the bath

A no effort outcome!! We still need to sort out the self settling but it will come. Eventually!!