The rules for setting up an evaluation vary from state to state. Generally you can go through the counselor. You may have to push to get the ball rolling. Some districts are hesitant to refer for more testing (it costs time and money), but clearly there is a problem here that goes beyond the scope of normal test anxiety.

I'd still work on your husband about therapy though. Remind him that your son isn't A problem, but he definitely HAS a problem. It's not about who he is; it's about what he's experiencing.

I completely understand your fears of somehow "causing" these problems. My sons have definitely acquired some mental health issues from my husband and I both genetically and environmentally. It is what it is. It's NOT your fault. It doesn't mean you are a bad mom. It just happens sometimes. The good news is that you recognize the symptoms and are taking steps to help your son early on. He's blessed by that. Remember that.