Do not say a little in many words but a great deal in a few

i cannot help feeling the cultural difference with him because he often breaks his promises and i notice he doesnt care about it at all. so im confused and it breaks my heart. he is an american. i heard americans sometimes break their promise, but he breaks them too many times so i dont think other americans are like him. i think people cant always keep our promises, so its ok with me that someone sometimes break their promises. i told him that please dont say "i will" if you cant, but he really doesnt care and never regret about it, so i am sad badly. if you like tell me whether this is natural or not.

first, i was very disappointed at him but soon i was getting sad. disappointment is better than sorrow. because disappointment cannot kill my heart. but sorrow can kill it.