Hey, sorry to hear that you've been struggling with bulimia. Why don't you want to go to your GP? If you are unwilling to go through the usual medical channels for support, maybe you could look into eating disorder charities in the area who may be able to offer support.
Can you describe a bit more about where you seem to get 'stuck' in recovery to cause you to end up back in the cycle? That way we might be able to suggest some strategies to help.