Legal Question in Immigration Law in California

If you wish to change status from H1B to F1 Student, it's possible if you apply and are accepted by a US college/university and able to pay tuition. College education is not free, unless you are somehow offered a full scolarship. You will not be able to work to support yourself while on F1/F2 status, and should be able to show the source of funds to pay college tuition for at least a year.

No, there are no special visas for unpaid charity work.

You have a few options: (1) find another employer who can sponsor you for an H-1B--if you can do this relatively quickly and the employer files the petition now, you can port and begin working upon the receipt of the H-1B petition; (2) file a change of status petition to F-1 student status. You would have to show the source of funds to pay the tuition and living expenses and you are not authorized to work in this status; (3) find another institution to sponsor you in J-1 status for a J-1 position. Note that your husband's status is dependent on your status, so your husband would also have to change to a different status if you did as the principle beneficiary. If you have other questions, you may phone at 415-387-1364.