Sleeping disorder. Please suggest.

I'm a student. I sleep a lot in classes even though I get sufficient sleep during night. I am awake when I'm talking to others but when I'm silent or try concentrating after few minutes my mind starts diverting and thinks something without my sense I will be sleeping I can listen slightly and also scrible. I even get short dreams. I'm awaked just by a touch and I feel whole my body activated all of a sudden. My heart beats fast I'll feel normal but after few seconds same repeats. This happenes only when I'm inactive or it's boring . I'm experiencing this from past 5 years. Sometimes it's more and sometimes it won't happen. Please suggest what to do. I stay in Bangalore and my parents don't believe this. I don't know which doctor to consult.