The family that have placed you in this position can not be said to be Sikh, in that they are not compassionate, tolerant, and ready to learn. Unfortunately they are tainted with cultural and racial prejudices, and are being led by supposed rumours - "What would the neighbours think". These are totally lacking in the values of Sikh's, which require bravery and courage.
It is a shame that you should associate these people with those that are Sikhs. However, you will find that there are very few Sikhs that would in practice find it difficult to follow the true righteous path in such matters. Therefore Sikhs generally become no different from the aggregate of their culture.
Otherwise the more understanding of us understand your plight and sympathise. Unfortunately we can only assist in a limited manner - with words of support. It is noble of you to continue to follow a Sikh path in the light of your experience with these parochial pindoo Punjabi Sikhs. However, regardless of what 'thescoopes' implores, it is not neccesary at this juncture alone to question the existence of God and challenge the religion. The religion can be challenged on many points but not on the actions of those that create the perception of being adherents.
Surely if the religion itself sanctioned the conduct of your husband' family then it should be questioned, until then good luck.