I understand, but... the strong emotions coming from them are probably based in their strong love for you. If they didnt love you, Im not so sure their responses would be so big...
You have to know that as much as your wifes illness is affecting the family, so is yours. PTSD makes us feel *very* alone. Are you really as alone as you feel? Can you safely express your feelings and what you need to your family? (Maybe better done in writing?)
You may find that how you're interpretting things aren't completely accurate to reality, and may be just a little distorted by PTSD. As an outsider, I couldnt possibly know. There are different sides to every story... where you see a lack of support may be frustration from a family member who isn't knowledgeable enough about PTSD to respond in a way that is appropriate to your illness. They may just love you and don't fully understand PTSD, so they want to change your behavior by "punishing" you for it because they don't know another way? Is that somehow accurate or maybe slightly possible?
Nobody is perfect and nobody is totally flawed. I suspect a great love for you from your family, and a great frustration with your illness based on their lack of understanding about PTSD. You are frustrated with your wifes Bipolar. I imagine the same is true for her about your PTSD.
But you are trying to help yourself and you deserve a lot of credit for it! You're brave enough to take the steps needed.
I think you are very loved in your family. I think you also love your family very much. I think an outside professional can only help this work better... even at the very least to educate everyone and help with how to handle conflict among you all...
