Fillers stretched my nose. How can I tighten my nose again without injecting any fillers?

Without any standardized before and after pictures, it would be difficult for any expert to assess which treatment is best for shrinking your nose. If you are concerned about loose skin and seek a tightening effect, one suggestion I like to make is applying a strong Retinol (topical cream) to the nose specifically. Retinol offers a fast overturn of skin cells, which results in a tightening effect with nose skin. Be sure to start with a gradual and light application regimen with it because it often causes peeling and if too harsh application, some redness. I personally prefer time-released microsponge retinol creams which can reduce the severity of its peeling and redness effects.Best, Dr. Anil Shah

Hi. You should start by having the filler reversed with hyaluronidase. Once the filler is completely dissolved treatments that stimulate collagen will help tighten the skin. 
You could have microneedling and use topical like Alastin Restorative complex. It may take a little time but it can be corrected!! 

It is difficult to answer this question without the benefit of photos or a physical exam.  In general, loose skin may be treated with topical therapies, such as retinol and vitamin C; or more aggressive resurfacing procedures, such as microneedling, microneedling with radiofrequency heat, chemical peels, and lasers.  If there is concern for remaining hyaluronic acid filler distorting anatomy or creating an unwanted aesthetic change, one may consider dissolving the filler with injection of hyaluronidase.  Consider consult with a Dermatologist, Facial Plastic Surgeon, Oculoplastic Surgeon, or Plastic surgeon to review your history, undergo an exam, and discuss your treatment options.  Good luck!