Dear "Brain on Speed,"
You control your mind, your mind does not control you. The moment a conversation starts getting re-played over and over in your head, or your mind begins to analyze your boyfriend's traits, tell yourself - "Stop over-thinking. This process of continual analyzing does not get me anywhere or bring me extra clarity. Brain, stop." It might take many tries, but eventually you will literally train your thoughts to stop dominating your every move. Over-thinking is a bad habit just like any other. Don't get me wrong, being a thoughtful and self-aware person is a plus. You just need to channel your thoughts to constructive insights.
In regards to your wondering if your boyfriend is "the one" - I can only offer you the following advice:
No one is perfect. If you keep looking and waiting for perfection you will never find true contentment in a relationship. Having said that, the man you commit to spending your life with must have many of the top qualities on your "dream guy" list. Get a pen and paper and write a list of the 20 things you are looking for in a soul mate. If your boyfriend encompasses the majority of these characteristics AND you feel in love with him, then he is a keeper and move forward with your relationship. Stop analyzing and start living life because every moment that ticks away is precious.