Try another bank, or a Mortgage broker. Not every bank like this kind of mortgage.
Another reason is you may not have long enough credit history.
奖学金 is not a income, because it will end for sure.They are not even sure you will get a job after you leaving school. If it is a job income, the bank will believe your future income will be at least same as current income even you change a job.You have the ability to get such income.