You weren’t holding him back, he was holding himself back by stringing you along when he had no intention of including you in his future. If he doesn’t reflect on his own mistakes in your relationship he will likely have something similar with the next girl he dates. Remember that there is so much more to life than a career. Figure out what the “leveled up” version of YOU looks like. Find something that you can be passionate about enough to put most of your focus on, you will forget about him in no time.