Isa, I don’t feel that Raskolnikov has any type of emotional connection with his family. In fact, I don’t think he is capable of forming emotional connections. His reaction towards his family and their wanting to help is a clear indication of his inability to receive and his feeling he does not deserve any help. He is both critical and harsh in regards to his mother and sister and the reunion turns out to be a failure.
I agree that we are all very frustrated with his actions, however, I feel that Dostoevsky wants us to understand Raskolnikov more than reject him. I feel that Razumihin's fixation on Douina actually changes the novel up a bit because it distracts the reader from the Raskolnikov’s tedious condition.
I have also noticed this behavior in Raskolnikov, but I think that it is normal to have a physiological reaction to stress or trauma.
I think that high levels of impulse and emotion are ignited in certain moments. I am not sure about what triggered his murderous instinct, possibly something from his past, but I do agree that he is definitely receiving a form of self-inflicted punishment.