Never Underestimate GMAT, that was my MISTAKE

So here is a short story.
I am a graduate student at a one of the best universities. Since it I am getting to my final year this fall, I got mixed feelings on whether I should enter the job market straight or apply for a phd. I sat with my professor to discuss the issue and to cut the long story short, we all agreed that I should apply for phd beginning Sept fall. So boom, there I was, I skimmed through some good universities and they had this GMAT requirement and I didn't bother to think it was something serious.

What I knew is that I had to write this Gmat and give the adcoms what they want. So I went on to register for a date without actually understanding what this exam was all about. I chose to write in three weeks. I was having dinner with a friend and he asked me what I was gonna do for the vacation, and I told him that well, I would write some high school sort of exam, they call it gmat. Surprisingly, he had taken the exam before. When he saw my confidence, he thought I was prepared so he didn't bother saying much but his look sort of said 'be careful'. We moved to another topic.

The more I spoke about gmat to my friends, the more they got worried because they knew I wasn't preparing, we were spending time together having fun. A girl who knew me well, dropped by and handed me OG12. I opened it and attempted first 100 questions. I began to feel something was wrong, it was never what I thought it to be. Suddenly depression and stress hit me hard, I had few days remaining....less than 15 days. I didn't know where to start. I began to learn of sections such as SC, CR, and they got hard every time I attempted. I had no rules, and I felt like the exam isn't really testing language, there are some tricks to be pulled from somewhere. I looked up on internet and read about e-Gmat I signed up but I felt listening to videos was taking time which I did not have. The thought of rescheduling the exam never came to me until 3 days before the exam. I was in bed. I was sinking, I had tried to be everywhere on all sections, and that got me even more confused. In a week before the exam I took Gmat prep exam and scored 450. I was depressed, I had read where people said that score does not vary a lot with the actual score that people get in the exam. I lost all confidence and did almost nothing for the entire week. I saw failure coming, it had arrived. Pulling my score to a miracle one required more than a prayer.
D Day arrived, I was weak. And angry at myself at the same time. How could I have been this stupid. I went to the exam feeling like I was just going to pull a 400. I sat for the exam (two days ago, just recovering from the heartbreak) and scored exactly 450. I guessed most CR questions. I scored 4 in IR. I haven't told my professor yet (please don't tell him...will be a big embarrassment.

As you can see, I made huge mistakes. Often times we learn from those that have done so well but I felt I can share something that may help others in the future.

My mistakes
1. I UNDERMINED GMAT. I have learnt a lesson, the hard way. My program at university is heavily quantitative and I thought maths (calculus, optimisation, differentials ..add to the list) was my thing. I was wrong. The new conclusion is "Being good at maths does not mean you will get a high Q score, and being a native speaker does not mean you will get a good V score"
2. I did not take time to prepare. I jumped to questions without a clue on the tricks and concepts of all sections. GMAT sections are like an onion, they are peeled layer by layer.
3. I panicked and lost confidence. Well, for a person like me that would have been very difficult to avoid. I had no time, the more I understood GMAT, the more it became Mount Everest. And there I was, gasping for air. I choked.

4. I pressured myself, but it didn't work. Maybe If I had discovered that time was not on my side and focused on my weaknesses it might have been a bad score but much better than the one I got. I was overwhelmed, tried to absorb everything at one goal, I remember for a week after discovering that I was in big trouble, I overworked my mind doing questions in OG. It was not a successful strategy, I would get answers wrong and still not grasp the concepts well because I was tired.
5. I didn't even have a real target. I think this has been said by several people on the forum that a realistic target is key for preparation. I just wanted a high score but didn't invest time and effort to pull it. GMAT is really not a miracle exam, hard work, hard work and more hard work.

I might have left other weaknesses but these were the top observations I made when I sat down to rethink my strategy. I will be retaking GMAT again in November. I will give myself about two months. My focus is on building the basics, building accuracy and then speed. I don't know if you will advise soft copies but I have downloaded MGMAT full package and will skim through every text and I plan to spend some time on CR and SC, and also learning the ropes in DS (the questions looked easy but that was a dream). I chose MGMAT because after my encounter with this website (which I'm still learning to explore fully), it appears that most people recommend MGMAT and OG. I will use OG mostly for questions but not now. My target score is 700. I can get into a good phd programme with it. The other non GmAT part of the application I can handle with ease.

Its a long story. Lemme know what you guys think and recommend to me. Feel free to drop a comment, will read everything and take advice into consideration.