If i already have hypothyroidism, addison's disease, raynaud's disease and vitiligo is it likely that i will get diabetes also?

Yes: While it is not likely that you will get diabetes, you do have a higher chance of getting diabetes. There is a condition called "polyglandular syndrome" which include: hashimoto's thyroid disease (hypothyroidism), addison's disease and type 1 diabetes. You already have hypothyroidism and addison's disease, so you should be followed closely for the development of diabetes.

Not necessarily: Not necessarily. Getting diabetes depends on many things including family history, eating habits, and toxic load. Consider finding a good integrative medicine physician to help you out.