Coughing and sometimes spitting out black mucaus?

by the way i am 13 years old and havnt smoked but.... but i have been coughing up black mucas and i keep having moments of dizziness, also haveing chest pains i havnt told anyone because i dont want to worry anyone but now i loose my breath fast and i have a breatheing problem i dont know what to do i dont wanna see a docor because i dont want my parents to spend alot of money on me... i dont want to be a burden.. but im confused and scared.... so please help me diagnoss what i have so dont have to go to the doctors.. oh and i get tired and i have been loosing alot of weight latly...