Most Helpful Guy
His behavior is creating a dynamic between the two of you, where he's the one postponing things according to his hobbies, and you're the one being constantly on hold, adjusting your life and schedule to fit his interests. If you let it happen, it might always be like that and that will make you bitter and annoyed, and understandably so. I'm not suggesting you cause drama over it, but I think you definitely shouldn't be too available. He needs to clearly see that you have a life of your own and you won't put up with him postponing dates because he feels like playing sports.
Most Helpful Girl
I don't think you're overreacting. He seems very unreliable and that is a red flag if you value reliability in a partner. He should have known before he made your second date that he had a softball game. So clearly you aren't very high on his list of priorities. I'm not saying he should put you first before everything else in his life but if he really wanted to get to know you more then he would actually make it happen. He doesn't seem to be dependable at all.