Question:Boy - girl relationships don't affect studies do they?
I assume that your parents object to you dating while you are in school. Unfortunately, they are making a valid point.
Back in the days when Israel called up its volunteer army, certain people were asked not to serve: "Then the officers shall speak to the people, saying: 'What man is there who has built a new house and has not dedicated it? Let him go and return to his house, lest he die in the battle and another man dedicate it. Also what man is there who has planted a vineyard and has not eaten of it? Let him go and return to his house, lest he die in the battle and another man eat of it. And what man is there who is betrothed to a woman and has not married her? Let him go and return to his house, lest he die in the battle and another man marry her.' The officers shall speak further to the people, and say, 'What man is there who is fearful and fainthearted? Let him go and return to his house, lest the heart of his brethren faint like his heart.' And so it shall be, when the officers have finished speaking to the people, that they shall make captains of the armies to lead the people" (Deuteronomy 20:5-9). If you think about it a moment, the rules make good common sense. A soldier whose mind is not fully on his task is likely to get killed. Having a love interest is definitely a strong distraction.
The apostle Paul made a similar point. God had revealed that Christians would shortly be facing strong persecutions and so Paul recommended, "I suppose therefore that this is good because of the present distress--that it is good for a man to remain as he is" (I Corinthians 7:26). In particular, he suggested that the unmarried remain unmarried if they were able to do so during the days of persecution. He then explains why. "But I want you to be without care. He who is unmarried cares for the things of the Lord--how he may please the Lord. But he who is married cares about the things of the world--how he may please his wife. There is a difference between a wife and a virgin. The unmarried woman cares about the things of the Lord, that she may be holy both in body and in spirit. But she who is married cares about the things of the world--how she may please her husband. And this I say for your own profit, not that I may put a leash on you, but for what is proper, and that you may serve the Lord without distraction" (I Corinthians 7:32-35). Paul goes on in chapter seven to explain that there is nothing wrong with being married, but the Christian must be honest with himself -- his marriage will impact his life.
I don't know what importance you place upon your studies, but you do need to be honest with yourself. Having a relationship with someone of the opposite sex will occupy your thoughts -- often at the least convenient times. If the impact on your studies is not that important to you and the desires of your body is strongly pushing you towards sex, then you are already distracted and you are likely to fall into the trap of sexual sin (having sex outside of marriage). In such a case, you are better off finding a spouse so as to have a proper outlet for your sexual desire. Or as Paul put it, "For I wish that all men were even as I myself. But each one has his own gift from God, one in this manner and another in that. But I say to the unmarried and to the widows: It is good for them if they remain even as I am; but if they cannot exercise self-control, let them marry. For it is better to marry than to burn with passion" (I Corinthians 7:7-9).