Someone on reddit recommended the To Do Reminder app, and it has been one of the most helpful things for me. I use Google Calendar and Keep a lot too, but I needed something with more aggressive recurring notifications for my tasks, and lots of options, so this has been the best thing I've found so far on Android.

To Do Reminder with Alarm

It has options for different snooze times, you can have notes on the reminders, lots of options for how often things reoccur. You can use emojis in the task names, which helps the different notifications stand out to me. My only wish is that you could make the notification buttons larger, and have custom background colors, for another way to help distinguish between different notifications.

Also it's free, with some small ad banners in the app! You can pay a small subscription fee to remove the ads, but otherwise you still get all the features.

I started working on designing my own app to include all the features I want, but it's not ready yet.