Approximately a few months ago, I was an intern in a research institute. One of the supervisors in a department became a PI of a project which seems to have huge implications. He needed help in performing simulation analysis and 3D modelling. As I was starting school soon, he persuaded me to work with him on this project, concurrently with my studies, telling me about the huge benefits of the project's impact and that he will include my name in the publication. Having the desire to really make an impact and wanting my name on the publication, I agreed to work on his project and extended my internship for another 4 months
During those few months, I worked tirelessly providing all sorts of simulation analysis, and from what I gather, this supervisor is good to work with. Fast forward, post 4 months, I've long ended my extended internship, and continued with my undergraduate study. 2 weeks ago, I asked him if he will be including me in the publication, he told me that 'it depends on whether the publication content has my contribution'.
Upon receiving that, my heart shattered still thinking that it's simply just a friendly way of saying 'no'. From that train of thought, it spiraled to hating myself onto putting my trust on to these people. I feel used. I feel exploited. I feel cheated.
Am I right to feel this way? Or am I simply overthinking about it.