I struggle with ADHD too. I'm still far from perfect but being mindful of things like fears. Facing them. Working with your brain instead of fighting it, and importantly trying to enjoy or appreciate your own effort helps. My basic understanding is we literally struggle with dopamine. Trying to pair dopamine with effort helps a lot. Fighting our brain just gives us less control. It's telling your brain that your brain is a threat which just makes things worse.

I out loud even at times tell myself "I'm trying. That's all I can do especially with my brain. Any effort is good and should be celebrated" has massively helped me. If anyone tells you you're not doing your best don't listen. One of the worst things to tell a neurodivergent person.

That mindset also helped with my self esteem. Even if my fears are true and I'm being a terrible person by not doing something, like not controlling my brain, giving myself the ability to appreciate my effort will help me change.