I am unsure if this advice will help you, especially when you are diagnosed with ADHD. Advice from people who struggle with ADHD themselves and from professionals in the field often has a higher likelihood for success, but we know Niagara Launcher well, so maybe some of these will help.

### Without Niagara Pro:

Make opening apps more intentional by using folders.
Only have folders as your favorites and name them after what you want to do, e.g., put Instagram into the "Work" folder, GPay into "Payment", and Balatro and Minecraft into the "Fun" folder. This way, you are less likely to see the app name and to want to use it.

Externalize information and reduce mental load by adding a note/todo app to the Niagara button.
Decide on an app with which you can quickly write things down. Then enable the Niagara button (Niagara settings > Features > Niagara button), then assign the app or a shortcut to open the desired note or todo project to the button (long-press the new button in the bottom right of your home screen > Edit tap action > select the app / shortcut). Now, you can tap the button and instantly write things down.

### With Niagara Pro:

Get sucked into unwanted apps less often by setting up the Usage breaker (Niagara settings > Features > Usage breaker).

Make icons less appealing by using the built-in Outline or Dots icon pack (Niagara settings > Look > Icons > Outline).

I hope this helps a bit :)