In "man speak" that statement translates to, "pass the ketchup, please." Oh, wait, that's the wrong page in the translator... Do you believe the sincerity of his statement can be judged by someone else, just from his statement? If what he said is in the realm of possibilities, then you can't assume he's lying. But if, for example, he says he can't get close because his pet elephant needs an oil change (or something ridiculous like that), then you know he's not sincere. If he is still hung up with his previous relationship then it might no be the right time for him to start dating again. For you it might mean that your in for a ride in hell. He may have played his cards right by making the ultimate excuse which would cover for all the mistakes that he would be making through the course of the relationship (if there was to be one). I would advice to be careful. If you decide to go on with this guy then steel yourself for what would come so you don't get any nasty surprises. Answer
Believe him and move on. This line is perfect for you to turn yourself inside out trying to make the difference for him, that you will be the ONE. Instead find someone who is whole inside and who can share a relationship with you, giving you what you need from the start.