My Story!

I am a 21 year old college student in India, and there are three parts in my story of becoming addicted to masturbation, overcoming it and again becoming addicted.
1.1
I was smart and quite good at math in middle school. In India, if you are good at math in school and you are from a middle class family, then you have to be an engineer. There is a Joint Entrance Exam (JEE) in India for admissions to engineering colleges, and most of the guys who are serious about cracking it join a coaching and study 2 years for it. I thought I was serious too, so I too joined a coaching.
1.2
During the 2 years I pulled all nighters when I felt like it, but I didn't for most of the time. My habit of masturbation developed from the first year of high school, but it wasn't serious. Now, maybe due to pressure of performing well it was becoming serious. And sometimes when I really needed to study, I found myself masturbating instead. Now, this is where it gets a little dark.
1.3
To stop myself from doing this, I used to slap myself hard a few times initially. Needless to say, it didn't work so kept on increasing the number of slaps by 10 or 20. Even after reaching a count of 100, I couldn't stop. I used to be quite smart at the start of the 2 years, but my performance kept getting worse and as you may guess, I performed poorly in JEE. I cracked the exam but barely, so it was worthless.
2.1
After taking the exam I found that it wasn't hard enough, and I performed badly because I didn't study properly for it. My friends from the school cleared the exam with flying colours and got admissions into older IIT's which are considered the best for engineering in India. I knew could have gotten into them only if I didn't screwed myself up all the time. Since you can take two consecutive attempts for JEE, so I took a gap of a year and decided to take the exam once again, but properly this time. Now, this is where it gets a little bright.
2.2
I knew I had to stop my urges at all cost, and at the time of the urge no motivational or spiritual talk would pop into my mind. I deduced the trick has to be much simpler, so I made up a simple rule for myself. As I was an IIT fanboy, I decided that if I write "IIT" on my hands then I won't do any vulgar activity out of respect for the institute. This may sound stupid, but that's exactly what I did everyday for a year and except for a few days when I didn't write it, I didn't masturbate for nearly an entire year. And this time I cracked up the exam and got admission to an older IIT.
3.1
Once I had cleared JEE, I had no hopes or dreams left as this was the only big thing I knew since childhood. I thought that my habit would automatically stop once I got into a good college, but contrary to my belief it resurfaced and I found myself becoming addicted to masturbation once again. This time I never beat myself as I knew it wouldn't help. And I didn't want to use the "tattoo" method because it was temporary and the resolve was weak.
3.2
I am in my third year now and my CPI is decent, I play soccer with my friends, I also play guitar sometimes but I am not happy anymore. I always want to give up on masturbating but the longest I lasted was 2 weeks. I am surrounded by geniuses, who either do not masturbate or do it controllably. I know I am old now and I should work upon my career but my resolve is not as strong as it was once before. Day by day, I feel more and more stupid for not being able to stop myself till this date. I just feel sorry for the smart kid I was during middle school and gap year. I feel like I am not the same person anymore, neither as smart nor as strong.
Sorry for this long post, and I would be very grateful if someone can help me.