They've been broken-up a month when you started dating, told you he loves you after four months. I would say he didn't give himself time to heal BUT all of us move on and cope differently. You're not wrong to feel that you are a rebound.

Let me ask you this though, he says he "loves" you, what does he do that shows his affection for you? Pareho kayong estudyante so I'm not expecting over-the-top stuff but for you, does what he show you - actions and words (not just the ILYs and sweet nothings) - do you think it translates that he genuinely cares for you? It's so easy to say ILY and not really mean it. With that said, what has he done for you that makes you say 'Duda ako dito.' or 'Talagang gusto niya ako.'?