I don’t know if I know a lot about life, I struggle with my own issues as well… but I am much older than you so I’ve had some experience with dating and so on, and have heard a lot of friends’ stories over the years to form some opinions.

You didn’t do anything wrong, and I don’t think you need to become more like him, be a hurtful, insensitive person yourself, to avoid these situations.

What you do need to do is keep your boundaries. Understand and determine with yourself what behavior is acceptable towards you and what isn’t, and simply walk away from people who do not act in a respectful way.
You can still be who you are and keep all the good stuff about you for someone who will appreciate it. But you must learn to walk away from hurtful, disrespectful people. Not try to explain to them or demand explanations, simply walk away. Believe me, this is the best strategy. If someone doesn’t respect you, doesn’t see you, you cannot change that about them. It is sad but true and so much suffering can be prevented if you stick to that principle. Just ignore them the way they ignore you, and see how you will attract the right kind of people instead.