I don't have any answers to your question, but I do have some thoughts. First of all, sometimes I do a really good job of hiding that I am hurting and people don't even know. Secondly, mental illness or even just general sadness is kind of taboo in our society, supposedly everyone is supposed to be good all the time I guess. Thirdly, sometimes people think it's your own fault and that you "deserve" it. Fourth, sometimes people think it is some kind of moral failing that has put you in this situation and you have to live with the consequences, or you would feel better if only you would - fill in the blank.
Sometimes I think too people don't want to believe it, that something has happened to you, especially if it involves someone they know or care about. Or if they are part of the problem of course they want to downplay the significance of your problem as much as they can, to feel better about themselves. It doesn't make any sense to me either, but I am glad that you are okay physically. Be more careful