I'm no professional, but judging from my experience with narcissists, if you're consciously asking yourself if you're narcissistic on a regular basis then you're probably not a narcissist. Narcissists in my experience, lack the ability of introspection.

Your behaviors seem to be retaliatory and the result of the way the relationship dissolved, sure it was not healthy, but prior to the unhealthy behaviors you mentioned you were obsessed with them, narcissists are only ever obsessed with themselves. Perhaps you were obsessed with them because they made you feel good? But again I'm not a professional. I just don't think you should beat your self up about it, you're likely not a narcissist. You're receiving therapy and I applaud you for taking care of yourself!