How to help my son?

My son has been diagnosed with ADHD since he was 4, possibly autistic which I will find out more if he is next week. Plus he is also suffering from anxiety. My problem is that my Mom and his Dad have both told me that he wanted to harm himself because he cannot do good in school or he cannot get his homework correct like he wants it to be. He sees a counselor with DPH next week. What can I do until then to help him with this situation? This is one of us Mommies worst fear is to hear our kids that they want to hurt themselves. He is only 8 and if I don’t do anything I am afraid that I will loose my mind and would follow his footsteps after him. I am afraid to even leave him when I go to work more less let him out of my eye sight. Please can I have positive feedback. I am scared to death on this.