But he didn't even when he had the second chance your loaning the money afforded him; I don't see anything at all wrong in your behavior or attitude and, if you could afford the money, you could not know that he would not see the error of his ways. The only thing I can see that "might" have been a failure of boundaries on your part is if you could not afford to lend the money and then lent it anyway, causing a potential difficulty for yourself or your family, or, if you lent it and he didn't see his error and you lent more.

I lend and someone pays me back and then I lend more; my boundary is if you do not pay back, you don't get more. A person has to show they are trying to work on their problems themselves, "words" alone won't do it.