Advice on my relationship?

My boyfriend keeps promising to meet up with me and then always cancels, this is now the fifth time in the row he's done this. It makes me really unhappy because (I may just be paranoid) I feel like he still likes his ex, he told me when we started dating (within the first week) that he missed her and had feelings for her, but he thought she died, anyway that's a whole different story, but she's alive, and he started speaking to her again. I don't know what to do because I feel super unhappy but I really love him. Also, it's always the same excuses, for example, "I feel shit" or "I'm busy" when him realty he'll snapchat me a little later of him in bed eating a burger or something like that, like if you don't want to meet up with me at least be more creative with your excuses.