I know its very difficult for a female to get respect and acceptance in in law's family. We accept to be treated as we are in our own family. But it hardly happens.
I just want to ask you a question will you be able to control other's thought and behavior. Will you mother in law will ever be your mother, or sister in law will be your sister, or brother in law will be your brother. You don't think I am taking there sides.
So stop expecting anything from your in law's family, do your job as much as you can, try to express yourself in front of others and keep realistic expectations from your husband.
Next Steps
if you having issues with your husband and he is not understanding you kindly go for couple counseling.