I am sorry to hear that you are having severe sickness
I would agree with your doctor that there is not a lot that we can do. Thankfully, your delivery date is near, and once you have had the baby, these problems should resolve.
In the meantime, do the best you can and do not worry. As long as all tests have come back as normal, there is no cause for concern.
I wish you all the best and ease in your pregnancy.