Your doctor can screen for diabetes using the "old" way of urine testing. However, that method is not the most accurate, and if glucose is found in your urine, bloodwork is needed.

I am not sure why you are so concerned that you have diabetes. Do you have a family history? While it is true that Type 1 diabetes cannot be prevented, unless you have a family history, your risk of developing it is around 0.5% (very low). This is the uncommon "severe" form of diabetes that requires daily insulin injections for survival. That said, I have met people with needle phobia who have Type 1 diabetes. When they were told they'd have to inject or die, they got over it. The needles are short and thin. Some people with needle phobia do well with the insulin pump. The thing is, if you HAVE diabetes (Type 1), you will have little choice. Therapy for needle phobia may be needed. Also, there IS an insulin "injector" that uses a jet spray to break the skin, but it is very painful and causes major bruising and dosing problems. It is virtually never used anymore.

If you are at risk for Type 2 diabetes, do something about it. Lose weight, eat healthy, and exercise. In most cases, lifestyle and oral medication work well for Type 2 diabetes.

All of that said, if you need a medical test, you will have to figure out a way to overcome your fear. In most cases, it is the fear itself that causes the sensation of pain, most needles for bloodwork nowadays cause little pain. You can get a prescription for EMLA, a numbing cream used for children with cancer who need central IV lines. Apply it beforehand, and you will be fine.

EDIT: If you are ruling out diabetes BECAUSE of your needle phobia, then yes, you need professional help to overcome this fear. I would talk to your doctor, a school psychologist, or look in the phone book for a therapist/psychologist. This is an extreme case that is interfering with your life.