I've had a dry cough on and off for weeks it's sounds very chesty but is dry no phlegm, also my tonsils are enlarged and i also think i've developed sleep apnea?

Enlarged tonsils and sleep apnea may be correlated but not with your cough. Cough at night, enlarged tonsils and waking up during sleep due to cough (not a true sleep apnea) can be symptoms of gastric reflux. Whatever, it's time for you to see your doctor for a thorough exam. A chest X-ray and a sleep apnea study may be necessary.

Have you recently had symptoms of COVID 19? Testing recommended. A dry residual cough is also associated with bronchospasm. Allergy testing and controlling exposure to dust, mold and other allergens is suggested. Avoid exposure to smoke and keep sleep area clean. Monitor temperature and breathing. If shortness of breath occurs, please see acute care.