@Tharg If you find smoking cannabis harsh, investing in a glass water pipe (bong), where the water to filter the smoke and eliminates the harshness, making it alot smoother to use. The same can be said with using a vaporiser with a water pipe, to remove the harshness and heat asssociated with vaping at high temperaturers.
If you have a cannabis social club near you, they can offer advice on equipment and help with both sides of the spectrum. However, as @Glos-Guy suggests THC can stay in the system and be detectable by blood and urine tests for upto 30 days.