Re: 'I am not good enough for you.'
why not ask him,, so why dont you think you are not good enough for me.
it may be a wishy washy answer which means he is just trying to get out ..with one of those its not you its me things..which is the likely situation
or maybe he has confidence issues which you really dont want to deal with because that can turn into jealousy, possessiveness and all later. u dont want to suffer due to his hangups
or maybe there are expectations of life that you have stated or he perceived which he knows he cant fulfill.
If you like the guy, ask him what he means..maybe he is fretting about something and a conversation will ease that, and if that is the case you should ask him to be more communicative in future and not let things get to him.
if its err umm well you see abip erpp err ahumm umm etc thrown in his reasons, just say yeah now that you say this I think you are right we are not compatible and move on