This is such a good lesson for everyone. I've seen so many people stay in toxic relationships and unfulfilling jobs just because they don't want to give up. To be fully honest, I was in a relationship myself for years after giving second, third, and fourth chances. Eventually, I had to end it but it could've been done sooner.
Even if we give people who are undeserving of second chances and more, I guess we could look at it positively and realize that we learned something in the process. Finding out that people take you for granted is a bitter pill to swallow.
Im glad you learned something in the process, too many people will keep falling for people who make them unhappy. Hopefully you are a better person for it now.