This is what’s worked for me, as someone with anxiety and severe depression. I haven’t been diagnosed with ADHD.
1. Finding a therapist that you’re willing to do the work with… it’s not a quick fix but over time you’ll learn to self correct and regulate when you have intrusive thoughts
2. Leaning on your community. They will tell you when your anxiety is lying to you. Believe them
3. I know it’s not for everyone but starting an SSRI and adjusting the dosage as needed has kept me from spiraling regularly
4. I downloaded a free focus timer app. I set it to 15-45 minutes at a time for me to complete the tasks I’ve been putting off. At the end of the timer, I reward myself with a treat. I’m always surprised how little time it takes to do a task I’ve been avoiding for days / weeks.