It's a sad fact that addiction is a grievously misunderstood demon. The same people that care about you simply don't understand how to treat someone that they believe has betrayed their trust, through no true fault of the individual who has done the so called "betrayal" of becoming addicted to a substance they had no intention of abusing.
Just keep doing what you're doing, and take a firm stance that you're sick of their bullshit. Tell them straight up that this isn't a discussion, that you're doing your absolute best to quit, that you're doing a good job, and that their negativity and accusations do nothing more than to bring you down. That their judgemental and accusative viewpoints are toxic to you as an individual, and that if they truly love and wish the best for you, that they will stop it. And if they keep it up, I'd say cut them off for a while and just stay strong as an individual striving for sobriety.
Do the same with your girlfriend. You tell her the truth point blank, and you make sure to keep telling her the truth regardless of what happens in the future. A loving relationship is built on trust, and you have to be sure that your girlfriend is the kind of individual capable of that trust, not one who will doubt your every move and question your motivations and objectives in life. It's completely normal to feel smothered and bored in a relationship sometimes, not even mentioning the fact that you're going through one of the most difficult things a human being is capable of experiencing. If you love and know your girl, I'm positive she will be understanding enough to give you some room to be yourself.
Keep up the good work my friend. I'm ecstatic that you made it to the 30 day mark, and that you're staying strong. Remember that at the end of the day, you're doing this for you, not for the benefit of others.
I'm here for you if you need it man. Don't let the negativity of others obstruct your ability to be the best goddamn human being you are capable of being.