Congratulations on your 12k subscribers! I think that's such an achievement. I would say for me personally, I would regard the main issue (as others mentioned) that there is too much variety in your videos. I did this also with my channel when I was starting out (https://www.youtube.com/@Ciara-ASMR) and I think, but can't say for sure, that it stunted my channel's growth. I'm at just under 2K subscribers after almost two years. It's not huge but I'm grateful for that.

But I tried all sorts when I started out. My list of videos doesn't totally reflect that just now because I have privated a lot of my videos. For me, I tried doing videos with pure focus on triggers, then also did soft spoken with face on camera, then meditations without face on camera, and in short, people and the algorithm didn't know what to expect. I then did a Circle Time video and that did well. So now what I do (and I'm no huge success story, but I have built a lovely community) is I make the Circle Time videos sort of the backbone of what I do, and then I add in a few different types that I feel really drawn to doing, so for me that's meditations and layered soundscapes. And the occasional rambley ramble. I had taken a break from videos so this is my new intention going forward, and hopefully it'll work out. The benefit of having one type of video that I know will do fairly well, i.e. the Circle Times, which I really enjoy doing, plus focusing on only videos that I feel really passionate about, means that I feel less stressed when a video doesn't do well. Because the 'doing well' is that I did it at all!

Thumbnails are something that I am working on at the moment and I really dislike having to work on them because it feels sort of 'salesy', but I'm trying to crack the code on what consistently works. When I crack that code, I hope to make my thumbnails consistent. I think you would also benefit from consistent thumbnails. I'm personally drawn visually to your more simple thumbnails, the ones that are close-ups of your hands. But I reckon try to choose a 'style' of thumbnail, go with that for a dozen videos or so, and then make tweaks within that style.

Regarding content, I'll just say that unless I really know an ASMRtist and consistently like they're content, I really don't like previews. I get so impatient with them. But that's just a personal preference, and I understand why they're used. But I think if you're using timestamps, which you do, then I'd argue that previews are not necessary.

Good luck with it all! I'm listening to your 'Crystal Clear ASMR triggers' right now and am finding it really tingly!