I guess it takes a Pro (me) to answer another Pro (Alpay)
You are 15 now, and you started at age 14, and you want to play like Ma Long (style) and become world top 200 in 5 years....
I can tell you there are few thousand kids that are hoping to become world top 200 in China, few hundreds of them in Taiwan, Japan and Korea
In China they train since 5 or 6, and train 40 hours a week, for 10 years until they are 15 years old (your age)
That is 20000 hours of high level table tennis training.
In the other three, they do about 30 - 35 hours a week (17500 hours by 15)
how many hours have you put in?
Solution for you
1) I guess you main criteria is you need a lot of money!
2) give up studying and train full time now and spent maybe 5000 USD a month to hire a full time training partner and a coach
3) prepare funding to take part in world junior circuit - go to min 4 a year, that you need another 50 000 USD a year maybe
So you need between 500k to 1 million USD for the next 5 years to have a chance to reach world top 200
I know a player that are 15 now (ranking top 10 in u18) and spend very close to that and he started playing since 5 and he is talented (future top 10 material)