Educational App Revenue Help Needed

I have dreams of being an app entrepreneur, but am having a tough go at it. I have an educational app that is free and contains ads. Users can pay to remove ads if they want for $2.99.

Over the last 90 days it has 17,000 installs.
My retention rate isn't super great:
day 1 20%,
day 7 4%,
day 14 2%,
day 21 2%,
day 30 2%

Given the content in the app I think most people could finish everything in it in about 2-3 weeks if they spent about an hour a day doing activities.

Over the past 90 days I made about $90.00 in ad revenue and $325 from users who paid to remove ads.

The money I'm making seems really low to me, it looks like I make about $0.025 revenue per user.

I depend 100% on app store search to find users. I haven't paid for ads, or done any marketing.

A few questions I have:
Is my revenue incredibly horrible for a free educational app?

Would a different monetizing strategy be better (gated content through IAP? subscription? other?)

To me it seems like I'm getting a decent amount of users, but in reality, is the number just way too low to really build on? My app ranks in the top 3 for typical terms that would draw users to it, so I'm a little doubtful that I could acquire a ton more people, maybe it's too niche?

Any advice you have would be wonderful. Thanks in advance!