ADD Boyfriend Ended Relationship Abruptly

Hi, I've been involved with a man (who has ADD) for 4 months. He is 59, I'm 56. He just relocated from NC to Florida to continue our relationship after initially meeting in Florida while he was visiting a friend. We've had great communication, attraction, mutual like and respect for each other. We share many things in common. After being here for one week, he abruptly ended the relationship citing impulsivity that caused him to get over-involved. He said he did not love me enough to continue on. He blamed his behavior on his ADD and said he was sorry. He was loving and kind while I cried and fell apart. Now he is taking time to think before we speak again. I'm wondering if this is a common problem and if anyone can help me understand it.