Help! Ill and about to have a 18 hour journey!!?

Ok, so here's my dilemma. I go to Boarding school and i'm going home for christmas (we live in Saudi Arabia), but about 2 days ago I came down with a nasty cold. My head is pounding, my throat swollen, sinus' blocked, awful cough which hurts because of the sore throat. The cough is very wet and I have a history of bronchitis so I will probably be left with that. Also I'm having a mild difficulty breathing due to the congestion and so every now and then i get light headed. Now I have a 1 hour drive to the airport, the first plane ride is about 8 hours, then I have a huge wait in Abu Dhabi before I have a final 1 hour plane journey. How will I cope do you think and how do i stop spreading my cold among the other pengers?