Complex problems that require the right understanding for treatment.
You have a congenital (born with) problem with enlargement of the right nostril and upper lip. No one will ever be able to tell you why. For the lips, you can try lip fillers with the idea of creating the right balance. You would also benefit from a nose operation to reduce the size of your nostril as well as the nostril opening. I would advise you to see a board certified plastic surgeon, who has experience with craniofacial anomalies. Good luck!
Nostril and lip asymmetry
Some nostril and lip asymmetry is normal. Why are some more than others is difficult to predict. Underlying craniofacial anomalies may contribute to some. Sometimes fillers can help the lips a bit.
Why are my nostrils and mouth crooked?
Thank you for your question and for sharing your photograph. Though nothing replaces an in-person examination, dermal fillers can be used to augment your smaller left upper and lower lip to improve upon the size asymmetry while correction of your nostril differences will most likely require surgery to reduce the size of your right side to better match the left. This would require an incision being placed along the curvature of your nostril. See a board certified plastic surgeon in consultation. Hope this helps.