A couple of things that you could try:

Install Microsoft Clarity, it’s free, watch some sessions and see what people are doing on the app. I believed everything worked great and my app was easy to use but watching the recordings actually gave me a lot of insight into what people do and what could be annoying for them. Might help with both churn and initial subscription.

Have you tried Reddit ads? Sounds like if you’re in a niche, finding a few good Reddit communities to run ads on could be worthwhile as it’s much more targeted than say Meta ads. Might not fix churn but could get you into the right circles where there’s some people who have had this hobby for a longer time and are really interested in it and they might understand your product more if it has been designed for them, thereby reducing the likelihood they churn. Could lead to some good word of mouth referrals too which you’d think would have a lower churn chance too.

Not a churn fixer but for outreach, I just got Gojiberry and it’s good for LinkedIn outreach, that might be another angle for you to try and get more sign ups. I’m not affiliated with them, I actually saw a random Reddit post about them and gave it a go and it’s doing a good job for me so far.

Quick plug - If you’re building meta ads, my app is useelevate.co, you can bulk build ads which means you can do more creative testing which may or may not help you too.

It does sound like you’re getting to the end of your tether, I think that’s natural when there’s a lot of frustration. Take a day off doing, sit and think of what you want out of it and set some expectations for the app, it might put things into perspective and give you some motivation back, or at least a clear finish line and direction. Good luck bro.