My job is making me feel I'm a loser

My job is I'm an Admin Manager since I was the only one in this office. My title is pretty high authorative yet my salary is just on an Admin Staff level. I have been doing lots of efforts and I am doing my best really to finish the task. I dont expect anything, but they offer a raise in my 390 pesos wage, then added 10pesos since Im over my probationary. I am disappointed. After 6months of working, I thought they finally saw my efforts in my jobs and praised me and promised to give me a raise. November came, the promise raise never happened. They just change my salary into monthly wage from a daily rate and still I get the same amount every month. I have never been this disappointed and feel little about myself. I never felt this low, and no one ever made me feel as stupid as this. I will be resigning fromthis by the end of the year. But I am scared to start again. Since Im an undergrad, I dont know if I can find a good job here. Its making me frustrated that I might treated again this way since Im just an undergrad.