I empathise with your need to do this here, because the US medical system is very expensive.
The government "advises" people coming to the US to bring no more than a 90 day supply. You also need to bring a note from your doctor, and everything needs to be in the original containers. I'm not sure about the rules concerning needles in carry-on luggage, but I think most of them should be checked. The rule is "only bring enough for your own personal use", but apparently a year's worth of insulin would exceed this even if it really is for your personal use.
Prescription medications should be in their original containers with
the doctor's prescription printed on the container. It is advised
that you travel with no more than personal use quantities, a rule of
thumb is no more than a 90 day supply. If your medications or devices
are not in their original containers, you must have a copy of your
prescription with you or a letter from your doctor. A valid
prescription or doctors note is required on all medication entering
As to how to save money on your medicine, perhaps you can go home in the middle of your visit, and bring back 3 more months? I know that only covers you for 6 months, but it's better than 3. In any case, you will need medical insurance, and I think you will probably need to get your medicine in the US unless you can go back home every 3 months.