Early Intervention Progam advice

Hoping I can get some advice, support, knowledge etc. from anyone who’s been through this before. My daughter is 20 months and was just diagnosed with a “processing disorder” which the neurologists seem to think will evolve into a ADD/ADHD, OCD or Tourette’s diagnosis as she gets older. We spent a few days in the hospital thinking she was having seizures but it is a pretty significant tic that only looks like a seizure. She also has a speech delay. We were advised to get her into early intervention.

I’m going on a week of navigating this and I am beyond overwhelmed. The neurologist said I am going to have to work hard to advocate for my daughter and explain her issues to friends and family and eventually teachers so they under she has no control over this. I’ve already had to try to explain it to my in laws who seem to think it’s totally fine and normal “because Google says she will outgrow it.” If one more person discredits what literal doctors have told because Google says otherwise, I am liable to snap.

Has anyone been in a similar situation? How did you handle it? What made it more managible? What programs helped you the most?