He's not ready?

Sounds like he is straight. If you are female then he is gay.

I can see why this is worrying you, but you need to ask yourself do you trust him?
If so give him time, sometimes for things to work patience is needed...perhaps he just needs to get thingsin to perspective.
If he is stressed at the moment, removing your relationship temporarily, might be the opnly way to clear his overcrowded mind.
If you feel that he is taking to long, or that he is seeing other woman then, is uggest that you leave before he hurts you further, what he is saying could just as easily be lies as the truth... don't jump to any conclusions, don't put pressure on him quite yet, just keep the lines of communication open.
But ultimately, trust yout intuition.

RUN.....leave dat fool!

Although none of us can know for certain, I am betting that BassPlayer nailed it. Briefly, give your ex the benefit of the doubt. Before you move on, I would ask him to define exactly what he means by "figure himself out first". I would not settle for anything less than a thorough, respectable answer. If he cannot or will not define for you what this means, just accept the fact that the relationship is indefinitely over. Seeing that he has used words to place you on hold by stating a sort of future, quasi comittment, he owes you at least this token to hold you where you are IMO. Respect yourself. Let this boy know that you may or may not be available next summer.