It's hard to set boundaries, especially if you are used to playing 'the rescuer'. I like the idea of a 15 minute limit. I have had to do the same with my sister - (ie, if you call me when you are drinking, I will hang up. If you call me to gossip about other members of the family, I will hang up, and so on). She is toxic to me, and it seems your brother is toxic for you. Set a timer, and after 15 minutes get off the phone. And if you have to tell a white lie so be it. Oops, someone's at the door. I have an appointment. My battery on the phone is dying. Someone else is clicking in and i have to take the call. My dinner is ready. Etc.. I don't feel bad about lying, instead I ask why do I feel the need to lie to you?