Hi C,
I'm sorry to hear about everything you've been going through. I'm glad you were able to reach out to some folks about your situation, even if it hasn't always gone the way you hoped. I won't say I know exactly how you feel, but I know what it's like to feel like your mental health struggles are burdening your loved ones, and feeling horrible because of it. It's not an easy place to be, but here's the thing to remember: if your mental health is concerning to your loved ones, it's because they CARE. You said your mom tries to understand; even if she doesn't always get it right, her trying is her way of showing you she cares and that she loves you.
So while of course I don't know what's going through her head, I'd feel pretty safe betting that she would not agree that she'd be better off without you. Try and imagine things the other way around--if someone you loved was hurting themselves, would you want them telling themselves you'd be better off without them? Or would you want them instead to simply try and focus on healing in whatever ways they can?
It's wonderful that you were able to stay clean for a month; I hope you continue trying to heal! Let your counselor (and/or anyone else you can talk to about this) know how you're feeling; let them know when you have bad days and need extra support, as well as when you have good days and want to celebrate them. You will have both kinds of days; the good news is, eventually the good will start to outweigh the bad. :)
I hope this helped in some way. Take care, and please never give up on yourself. I'm rooting for you. :)
Sincerely,
Kim