No one can predict the future, some experts maybe are able to give their expert views on the job market.
Yet, Fear is never the right motivation, and for any job, neither is money.
Look inside yourself first and get in touch with how you feel about imagination, creativity, helping people make their spektakular homes and making great furniture and design. If you like art and color, that is a good indicator.
Get in touch with how you feel, and let this feeling come out bold and big enough.
About the money part, it is always a concern for everyone. Yet to make money one has to be very very very good at what you do, no matter what type of job. When you love doing your job, you will be very good at it, because learning the ropes is a joy not a drag.
First take paper and pen, and write down a short essay of all the things you would love to be doing, make a list.
write the answer to this question: How Interior Design helps everyone......
Then take a large sheet of graph paper and start drawing the floorplan of your dream house or room, put everything you want in it, animals, action figures or dolls, or anything else, and don't forget the doors, windows and closets.
If at the end of the day, it sucks, then maybe it's time to move to something else. If on the other hand you have thoroughly enjoyed yourself, then that is called passion and motivation.
Finally, post your work at school, tell everyone you are an interior designer and explain everything about the room to teachers, class and schoolmates and grown-ups, mom and dad and everybody you meet.
Let me know how it goes. O.K.?