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You might find it helpful to go through books written by therapists such as The Perfectionism Workbook and The CBT Workbook for Perfectionism to understand the causes of perfectionism and the beliefs and fears behind it.

This book isn't specifically about OCD but Overcoming Unwanted Intrusive Thoughts could be helpful as well. It talks about how to observe and accept thoughts, even if they're unwanted, repetitive or disturbing, instead of trying to suppress or fight against them.