Chest pain something to worry about?

Iv been having chest pain for the last 4 days and my lungs feel messed up the lungs part is probably from my smoking, but the chest pain first started in my left side but today its directly in the middle all the way to my back..It hurts really bad to inhale and with my lungs bothering me also im trying so hard to keep myself from coughing...I dont have a car so going to the hospital right now is outta the picture..Btw im only 18 but i am over weight and i got surgery in oct and my blood pressure was high and also one more time after that but havnt checked it since...Im scared please help..