Sorry for being blunt brother, but looks like Shaitaan has you like a football at his feet, kicking you around where he pleases.
Consider the following ahadith: "The strong believer is better and more beloved to Allaah than the weak believer, while there is good in both."
What do you think strength means? Is it only big biceps and forearms, or something more? Alhamdulillah I have both a Bachelor's and Master's degree in Engineering and have realized how much easier it is for me, by the Fadl of Allah subhaanahu wa ta'aala, to help myself and others. I can register for an Arabic course that costs $1000 without batting an eyelid Alhamdulillah, I can sponsor students doing their hifz in madarassas etc., all through the bounty of Allah which he has facilitated through the education and degrees that He enabled me to complete. I distinctly recall a piece of advice given to us students way back when we were doing our Bachelor's - a well wisher and Muslim philanthropist told us that you will be able to help others only if you have something in your pocket to give. If your own stomach is empty, do you think you will be able to worry about other's stomachs? A person leading a parasitic existence off of his parents might not realize it, but once he has to deal with expenses of his own, a nagging wife who has financial needs of her own, children who need to be fed, school fees to be paid, toys to be bought etc., will quickly forget his idealistic dreams and bite his hands in regret.
Has not the Prophet (saws) said: "Allah has decreed/commanded excellence in everything". Where is your motivation to excel when you study? A person is known by his defining traits - what is your USP? What is the field that you will make a mark in? I have had the honor of meeting senior executives in Silicon Valley who are also huffaz, giving Friday khutbahs and other lectures teaching Muslims their Deen. They are able to portray a beautiful, positive impression of Islam at their workplace through their hard work, skill and manners, without compromising their religious obligations.
As for the concern that you will be cut off from civilization to excel in competitive examinations, let me tell you that it should be the least of your concerns at this stage in your life - when you are laying the foundation for your future. A butterfly has to do it's time in a cocoon before it can appear fully formed and beautify the world - stop kidding yourself that you can skip the most essential formative stage and magically become useful to yourself, your family or to society.
Apologies if this comes across as a little harsh, but i'm tired of seeing Muslims who have been blessed with a family that cares about education, being provided with all the means and encouragement to succeed, but they simply throw it all away due to their ignorance and faulty understanding of Islam and what is expects of its adherents. Islams wants us to be winners, not whiners. First put yourself in a position where you are qualified and in a strong position academically, career-wise and financially; and then see how many avenues open up for you to serve Islam.
Be a man, stop wasting your life and start excelling!