In this situation the best resource for advice would be from an adult from a community agency. You need someone who is experienced in these matters and who can give you reliable, objective, trustworthy advice. Other teenagers are still learning about relationships and health and their advice will solely be based on their opinions and biases.
carbon dioxide passes from the blood into the alveoli and is then exhaled. Oxygenated blood travels from the lungs through the pulmonary veins and the cycle goes on every time you breath or inhale you inhale oxygen into your blood cells.