You could pursue a second opinion as to the cause of and best treatment for your spotting. However, if the spotting is caused hormonally, the first line of treatment is hormonal, and you have not yet exhausted all the potential hormonal treatments. A hysterectomy is a very serious surgical procedure with complications of its own. These issues are best discussed with your doctor.
Perhaps we can help you with handling the mid-cycle spotting. To that end, the first step is to assure that the spotting in fact would make you niddah. Please see the article on ketamim for further explanations and then, if desired, get back to us with more details.
As for birth control, there is a separate commandment, based on Leviticus 22:24, forbidding sterilization of animals as well as people. This is considered a Torah commandment for men and a rabbinic decree for women. Thus, only in very serious health situations would a hysterectomy or tubal ligation be permitted for women. Temporary methods of birth control such as the pill are preferred when contraception itself is permitted. Please feel free to contact us to discuss this topic further.