Is (the tip of) my nose too big? (Photo)

From your photos, it is impossible to tell you anything specific, but 15 years old you are still developing and your face will mature with time. However, your face is relatively well balanced and doesn't have a "weird" shape. Your feelings about this issue seem to be larger than the issue is in reality. You can speak with your parents about seeing a plastic surgeon as there may be things that do show in photos, but there is nothing to warrant surgery as it seems from the photos. You should see a board certified plastic surgeon in your area to get a formal opinion through an in-person consultation.Best of luck,
Vincent Marin, MDSan Diego Plastic Surgeon

Put away the magnifying mirror and look at your face realistically.  Your face is not "weird".  You have a very pleasant oval face and a beautiful mouth (lips).  In my opinion your nose is not too large for your face, though your tip is slightly bulbous.  I do not think it is worth the pain, cost, and surgery to achieve a relatively minor change in your nasal tip. You are a pretty girl, and should be enjoying your life, rather than worrying about your nose.