Over Exaggerating???

So I just had a falling out with this guy I was really into about a month ago. He was never honest about much including his feelings and he really played me. Recently I started talking to this new guy I really like (Yes, we've had sex already, not that it may really matter) and I feel like he's blown me off a few times because he works a lot and gets really tired. I've tried to hang out with him a few times during the day because we only hang out at night and he's said he's tired or feeling sick each time. I keep getting mad at him and flipping out on him each time he cancels plans. Am I overreacting? Or should I be cautious of him maybe going to break my heart like the last guy I was with?