Being on his insurance does not prevent you from taking the HSA contribution deduction. Being on his HD plan qualifies you for the deduction.
Form 1099-S is for real estate sales. Form 1099-SA is issued for a distribution from an HSA or HRA, not contributions. The distribution is not taxable if the money was used to pay for medical expenses.
Why are you not filing a joint return with your spouse? Filing separately is seldom the right way to go.