My mother-in-law is in poor health, so I gave her 2,500 yuan a month, but after overhearing my neighbor's small talk, I stopped giving it

(From a reader submission, images in this article are from the internet)
My mother-in-law is in poor health, so I gave her 2,500 yuan a month, but after overhearing her chatting with a neighbor, I stopped giving it
In the past, I always believed that filial piety and caring for one's family were virtues, and because of this view, I ended up marrying a wife who came from a poor family but was quite filial to her mother. After we got married, she was still fairly polite and considerate toward my family, but compared with my parents, she still paid more attention to her own family of origin. Since I also knew her family situation and specific circumstances, I had always taken a tolerant attitude toward her, and even often lent a helping hand, but only in the end did I realize just how absurdly wrong my thinking and actions had been.
My wife's family was of ordinary means. Because my father-in-law passed away early, she and my younger brother-in-law were both raised single-handedly by my mother-in-law. She was a woman with no particularly high-end profession or generous income, so back then she exhausted all her strength to raise her two children. Neither of them went to university. My wife gave up on it on her own because of the family's financial situation, while my younger brother-in-law had poor grades and no interest in studying. Both entered society around the time they finished high school.
At that time, all my wife thought about was earning money to support the family, while my younger brother-in-law started dating and got married early in his early twenties. By the time I married my wife, he already had a family to support at a young age, several years earlier than we did. Her responsibility as the eldest daughter in the family did not end just because she married me. After we got married, my wife often cried to me, saying that her mother was in poor health, that her own income was not high, and that just the cost of medicine and injections was expensive, and that as a child she could not ignore her own mother. After hearing these words, I sympathized with her, so I could only turn a blind eye to her frequent subsidizing of her family. In addition, I myself also voluntarily sent my mother-in-law 2,500 yuan every month as her living expenses.
Two days ago, I learned from my wife that my mother-in-law was sick again, and she asked me for money to send over. After giving it at the time, I thought about it and felt that as a son-in-law I should still visit in person to be proper, so I went over carrying fruit and nutritional supplements I had specially bought. Who would have thought that when I reached the door and was just about to knock, I heard my mother-in-law chatting and laughing with a neighbor, with no sign of illness at all. Not only that, she was also praising me to her neighbor at the time, saying that I was generous, did not like to fuss over things, and that her daughter had not chosen the wrong person. In the end, she even sighed and said that the money I gave was still not enough to cover my younger brother-in-law's mortgage, and that it was thanks to my wife subsidizing from time to time that his family of three could be supported.
I was very angry. The so-called illness of my mother-in-law was all a lie. My wife's concealment from me, my mother-in-law's taking a mile after being given an inch, and their indulgence and spoiling of my younger brother-in-law made me truly unable to bear it any longer. At that moment, I turned around and left with the things in hand, and I decided that from today on, I would no longer give my mother-in-law money. It turned out that everything was all for my lazy, idle younger brother-in-law who loves ease and hates work. Everyone, tell me, am I stupid or not, and angry or not?