You are right in your age most of the kids love to read fiction but if it affect your normal day by day work and
study then it is not good
What you do only that decide some time say two hours daily to read fiction not after that.
You should obey your mother as well and read some informative book as well may be one or two pages daily.
I hope you are able to do it Inshallah pray 5 times and pray for yourself.