The short answer is, if you accept that it's going to be hard, you can focus on the problem rather than how stuck and frustrated you are, and that helps you to not make it harder than it needs to be.
Of course, a person who needs help needs more than the short answer; in particular, we often need a lot of unlearning of bad mental habits, and we need to hear exactly what ACT is saying and, sometimes more importantly, what it is not saying... because we tend to hear what we expect to hear, not what is actually being said.
Here's the self-study book I used: https://www.amazon.com/Get-Your-Mind-Into-Life/dp/1572244259
It's a strong combo of CBT and Buddhist meditation concepts.
Things Might Go Terribly, Horribly Wrong: A Guide to Life Liberated from Anxiety, by Kelly G. Wilson [http://www.amazon.com/Things-Might-Terribly-Horribly-Wrong/d...]
Shawn Smith - The User's Guide to the Human Mind - Why Our Brains Make Us Unhappy, Anxious, and Neurotic and What We Can Do about It [http://www.amazon.com/The-Users-Guide-Human-Mind/dp/16088205...]
Russ Harris - Getting Unstuck in ACT - A Clinician's Guide to Overcoming Common Obstacles in Acceptance and Commitment Therapy [http://www.amazon.com/Getting-Unstuck-ACT-Clinicians-Overcom...]
Both by Jeffrey E. Young: Schema Therapy - A Practitioner's Guide, and Reinventing Your Life [http://www.amazon.com/Schema-Therapy-A-Practitioners-Guide/d...]
Steven C. Hayes, - Get Out of Your Mind and Into Your Life [http://www.amazon.com/Get-Your-Mind-Into-Life/dp/1572244259]
Charlotte Kasl - If the Buddha Got Stuck [http://www.amazon.com/If-Buddha-Got-Stuck-Spiritual/dp/01421...]
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