Is it possible to change tapered eyelid to parallel eyelid?

Attempting surgery to achieve this would be a mistake.  Especially to achieve Asian looking eyes, your eyes could easily be made to look more Asian with makeup.  The size and shape of your eyes and supratarsal crease (double eyelid) are not beyond the realm of what some girls achieve surgically.  

Hello,I would recommend following up closely with your surgeon to ensure the best results.    

You are still healing three weeks after Asian blepharoplasty. There will be swelling above and below the new crease at 3 weeks after surgery. It takes 4-6 months before the final result. At this point, it is hard to judge the final result. I am sure your result will be more natural with time. ...

The appearance and height of your creases will continue to change as your eyelids heal and the swelling resolves over the course of this year.  Symmetry will likely improve as you heal, but follow up closely with your surgeon to ensure the best results.