Hi, a small sized freckle recently appeared on the tip of my toe and hurts to touch a bit! It's dark in colour should I be worried?

Freckle. Most likely the spot is of a vascular origin. But if it hurts, it is either due to a recent injury or bite or something that might be of a systemic etiology like a septic embolism . You should see your doctor or a dermatologist to have the spot evaluated. It is easier to make a diagnosis if the lesion is fresh rather than waiting weeks before you have it seen.