Sorry if this isn’t the right place to ask, but I don’t know where to ask and I feel like I’m losing my mind. 
My boyfriend with borderline left me a few weeks ago, after a really long term relationship. 
He told me that I am a good person and “you deserve better”. He also told me that he’s feeling very ashamed for using me and he was thinking to break up with me for over a year. What does that mean? Is it really a “it’s not you, it’s me” case? Or there is other reason he won’t tell me? Like he found someone else? Or he just got bored? 
I’d really apreciate honest advices. It’s really hard for me to move on and to accept it all ends like this... 
Thank you!