Gastric~!!!!

Don't know what wrong to me this few days... Having a very bad gastric.. Super pain here... Eat medicine also no use on it... I take my meal like last time but how come now only pain? After my meal i will feel like wanna eat other thing again, and always feel like wanna eat alot of thing... Gastric nevermind but don't know why I will feel faint and super headache when I went for jogging or straight away walking stair to 3rd floor in college... I really wanna find out what is my problem. What can I do now? Let my parents know or how? If let them know just will make them more worry. HAIZ~~~~~ I don't want the pain anymore now!!! PLEASE GET AWAY FROM ME!!!!