Absolutely, as people with diabetes are at increased risk of developing serious complications if infected with influenza. You will have to receive the inactivated influenza vaccine (the intramuscular injection) rather than the nasal spray, as that is an attenuated (weakened) but live immunization, and therefore contraindicated in those with underlying conditions (such as diabetes) that would put one at increased risk of complications from influenza infection.
Diabetes affects lots of people all over the world. Living with diabetes is not very easy, many precautions and medications as mentioned on the link below along with healthy lifestyle is very crucial. Each year diabetic people offered flu vaccinations as they remain at high risk of getting the flu, especially if diabetes is not well managed or controlled.