We wish you a refuah shleimah!
Unfortunately you may not immerse before completing the
seven clean days. Such an immersion would not render you
tehorah and you would remain in
niddah.
While it is strongly preferable to have a nurse or another female assist you, if no one else is available your husband may physically assist you with your needs while you recover from the surgery even if you are
niddah. Any assistance that does not require
physical contact is certainly permitted, and even assistance that involves physical contact is permitted if necessary, taking care to minimize contact as much as possible. It is recommended that he wear gloves to avoid skin to skin contact. (If you require assistance bathing you should have a female friend/relative or a nurse assist you.)
Please feel free to get back to us with any further questions.
We hope your surgery goes smoothly and successfully!