wow, Hopeful - you and H have been through a lot. so sorry to hear that his reaction to the PTSD is to have an affair - but I agree with KML's remark about the affair being a way of "self-medicating". an affair is a fantasy world with no responsibilities, while your marriage is "real life". so that is what attracts him, not anything special about OW. you sound ten times better than her anyway.
don't let your friends pressure you, you are not being a "doormat". keep up that good positive attitude of working on yourself, and being ready to work on the marriage, but not approving of his affair. it is a very delicate balance.
the lighthouse analogy made me think of this: http://www.youtube.com/watch?v=zifZnkKxiro - a little corny, but inspiring. (in the movie, she is a lighthouse keeper, hoping that her fiance, a sailor whose ship was lost at sea, will return. of course, this being a Disney movie, he does.)
KML and Starsky wrote some good advice for you, and you are reading DB and DR and getting good info from there.
keep up your efforts and work on yourself, and hopefully H will realize who is really there for him and who is just a bit of fluff on the side. if he is unable to do that, at least you will know you gave it your best effort, and you will have improved yourself in the meantime.
