It's okay to be not okay, and to take some time to adjust to everything. For many of us autistic people it may take a lot longer to adjust, and that's okay!
Remember that it’s okay to be autistic. It’s okay to wear headphones or sunglasses, or use weighted blankets or fidget toys (lots of us autistic adults do!). It’s okay to want things a certain way. It’s okay to not look into people’s eyes. It’s okay to be you. Don’t let people, or society in general, take that away from you.
I want to let you know that autistic adults are here. Autistic adults exist. Most of us have had tough experiences in elementary school and junior high school. Personally, I felt rather isolated growing up in school.