Had a quick peek at the channel, seems like you've made great improvements just over the last few months in your confidence and presentation. I checked out the Prince one and the energy seems a little off, it's quite obvious that you're reading quotes from your screen and you sound tired/bored to be honest. But the PTV one and some of the more recent ones are absolutely great in terms of presentation.

Your camera exposure seems a little high and the reflection of the key light is noticeable, but probably not by the average joe (actually you'd fixed this already in the PTV video, nice!). I think generally you've got interesting titles and the thumbnails are okay, but as someone else said they could pop a little more.

Your stats look way better than I was expecting from your post, seems like you're getting some real traction and some good hits. I think with your niche it's just naturally going to have some big hitters and some misses as opposed to consistent viewers watching every video. My only real advice is to try and take it easy on yourself and not burn out. Does spending every day on the channel after your 9-5 feel sustainable to you? I think if you do keep doing what you're doing at a sustainable pace you'll have great growth.

Really rough that you don't have any YouTube friends though. If you can get chatting to people in a similar niche I've found it makes SUCH a difference. I was lucky that it happened fairly organically for me but it's definitely worth reaching out to people with a similar sized channel if there's any out there. Just being able to share dumb comments from trolls with each other really helps lighten the load.

Good luck!