Am I a bad person for lying this way or justified?

So I'm in a tough situation at the moment .
I'm a 22 year old female . The background story is that for years I've had eating disorder issues , binge eating , trying to throw up food etc my mother has quite a strict attitude towards weight and excerise so I hid it from her and when she found out I was hiding it from her she wasn't happy but I was just afraid of her reaction and being called a fatty etc . Over the years I continued and developed digestive issues like ibs, bloating and while I sometimes still binge eat and she sometimes caught me lying still , she believes that now I'm working on it and that I stopped doing it and she's going out and trying to help me with the bloating and buying all these healthy foods for me , reading all these health websites but she dosnet know that sometimes I just couldn't help myself and still binge eat and eat something unhealthy but I'm just afraid to tell her and feel bad about it?
Is it not such a big lie as I'm making it out to be and I'm safe to lie in this context or am I truly a bad guilty person?
At first I didn’t make much of it but now I’m starting to feel guilty but to tell her also makes me afraid