You can accept his excuses all you want, but you have to ask yourself, is this the relationship you want to be in? He may be into you, he may not, but the only thing you have to answer is, is this how you want to feel, perhaps forever?
If the guy you're dating doesn't seem to be completely into you, or you feel the need to start 'figuring him out,' please consider the glorious thought that he might just not be that into you. And then free yourself to go find someone that is.
Deciding to get back together with someone is a complicated and difficult decision. Just remember that the person you are getting back together with is the same person who, not long before, looked you in your beautiful face, took full stock of you and all your qualities, and told you that he was no longer in need of your company.
Don't ask yourself what you did wrong or how you could have done it differently. Don't waste your valuable heart and mind trying to figure out why he did what he did. Or thinking back on all the things he said, and wondering what was the truth and what was the lie. The only thing you need to know is that it's really good news: He's gone.
There's nothing worse, in dating terms, nothing worse, than that sick feeling you get in the pit of your stomach when it looks like the guy you were seeing or getting to know has decided to bail on you instead of talking to you about it. Nothing worse.