Just a thought. Sometimes we think that everyone is against us. But when I pay attention, I find that I care more about it than others do. When I try to complain to my daughter, she is like, whatever and she smells it. At the last company that I worked for, I knew they talked about me, but they still talked to me as a friend. One day, I guess it was particularly bad, a friend wrinkled her nose when she came into my cubicle. However, it didn't stop her from talking to me that day or any other.
There are some that will be jerks, but there are some that will not be mean and will want to be your friend. I hope that you try to make friends with others outside of your family.
Also, it sometimes helps to tell people that you are aware of the situation. Understanding that it is not an intentional not washing situation usually will build allies who are in your corner.
I wish you the best in your situation. Kids are tough. Keep looking for answers, never give up. There is a solution.