Glad you ripped the letter up. I know you aren't happy living this way, it isn't what you want. I also understand that they aren't really even being friends and they keep everything to themselves. This is hard. Honestly, the hardest thing I've ever done.
Right now, most of my goals are about me. The exceptions being having nice convos with H. I've been pretty good about this. Really though, it's about where I am, where I want to be and how the hell do I get there from here.
Glad you went to the gym, that's always helpful. The other thing that's helpful is to work at taking nothing personally. This isn't about you.
Check out Kansha's thread, it's got some really good stuff I think you could benefit from.