That sounds like a great person ! She has got you onto the right track and you should keep going with your recovery.
You were lucky to have her there when you needed her, if you feel that you have been too demanding then just be a little less.
We are all human , we all walk on this planet together and we are here to help each other if we can.
I am not sure if i put this in a good way but i will try with out trying to make you feel bad because that's not what i am trying to do ok. It is very hard on a person when faced with someone who is self harming and talking about suicide. it is hard for that person especially if they are the only one who knows as they often feel responsible and really want to help because they care, so they worry about the one hurting themselves. It is a lot of stress for that person. It sounds like she has been an amazing support for you which is great but she is your teacher and i think it is important to make sure you don't push that relationships. It is nice to know someone who is supportive and understanding. You can thank her for her help but maybe try and get more intense support from your therapist. and be a student and friend with your teacher.
I know it must be hard but i believe you can feel better soon. I hope i haven't upset you with this as i would hate for you to feel bad and i am not trying to make it sound bad.
If she is genuinely close to you as a teacher and you felt strongly enough about her to open up to her like this, then I wouldn't worry about imposing on her.
She's not your teach anymore so it's out of kindness that she's offered you her phone number and for you to call her anytime, and has offered the support that she has.
It's common for people with depression/znciety to feel like they're burdening other people with their problems, when really the person genuinely cares.
I think that she should have set limits with you and that as soon as you accessed help she should have backed off. It might be helpful to discuss the limits/ boundaries of your relationship with her. Talking to her/ or a therapist about this would be a good idea. You should possibly be seeing a therapist so they would be a good person to go to for advice.