First, congrats on starting your Lexapro journey, that takes real courage, and adding good books to your toolkit is such a smart move. Here are my top picks:
For intrusive thoughts specifically
“Overcoming Unwanted Intrusive Thoughts” by Sally Winston & Martin Seif, probably the most targeted book for exactly what you’re describing. It’s a robust application of CBT in action, offering both understanding and practical techniques to minimize the frequency and power of intrusive thoughts. 
“The Imp of the Mind” by Lee Baer, a comprehensive guide covering the latest treatments, strategies, and remedies to help reduce the impact of compulsive thoughts and behaviors.  Great for understanding why intrusive thoughts feel so sticky.
For OCD broadly (with workbook exercises)
“Getting Over OCD” by Jonathan Abramowitz, a personal favourite of many therapists, it includes lots of examples and worksheets to help you better understand your symptoms.  Very practical.
“The Mindfulness Workbook for OCD” by Jon Hershfield, highly recommended in OCD communities. It helps individuals refocus on their own thoughts and feelings, avoiding the constant pressure that negative thoughts create. 
“Brain Lock” by Jeffrey Schwartz, explains a simple four-step strategy for treating OCD that has been shown by brain-imaging tests to actually change the chemistry of the brain.  Very empowering read.
For self-compassion (great alongside Lexapro)
“The Self-Compassion Workbook for OCD” by Kimberley Quinlan, highly recommended in OCD book communities , especially for people who tend to be hard on themselves during recovery.
For phobias like hemetophobia, one extra book worth adding specifically for phobias:
“The Anxiety and Phobia Workbook” by Edmund Bourne , it’s a classic, very practical, and has dedicated sections on specific phobias with step-by-step ERP exercises you can do on your own.
One thing worth knowing about hemophobia specifically: since it can cause fainting (through a vasovagal response), the ERP approach used for it is slightly different, it includes a technique called applied tension, where you tense your muscles during exposure to keep your blood pressure up. A therapist who specializes in phobias can walk you through this safely, which is a nice complement to your Lexapro and the reading you’re doing.
Wishing you all the best on your healing journey