The easiest way to answer this is to ask yourself a very simple question: if your best friend had OCD, would you blame him or her for having the thoughts that you are blaming yourself for?
Hopefully you answered this question with a resounding no, and if you did, then why would you blame yourself for having obsessive thoughts if you would not blame anyone else for having the same thoughts?
You may think that you need to be stronger than everyone else or that you are weak because you have OCD, but you would probably not say those same things about a best friend who had OCD. So treat yourself like you were your best friend and recognize that these thoughts are related to OCD, not to you as a person.
Then once you stop beating yourself up over having these OCD thoughts, you will find that you will have greater strength to fight the thoughts or to engage in therapy.