Welcome to HCM,
You have two problems first one is Gilbet syndrome which is a type of Congenital hyperbilirubinaemia in which deficiency of particular enzyme is there and bilirubin level remains high it is mild and benign condition.
If your FBS and PPBS level are correct you are diabetic, as FBS>125 mg/dl and PPBS >200 mg/dl is diabetic.
If there is any doubt please repeat FBS and PPBS along with this you can also get a HbA1c
level which will confirm diagnosis of Diabetes
Your age is only 28 years so consult a Endocrinologist
to see which type of Diabetes you have Type I and Type II( MODY) possible.
Take care of diet and exercise and medicines/insulin
.Diabetes may not be cured at present but can be controlled and person can have normal life.
Good Luck to you