why do i feel a constant need to distance myself from the people around me?

i have been alone for a large part of my life, i fear its affected me mentally as i have a constant need to distance myself from the people around me. (even when i want to be close with them or build a friendship) i can see a very big difference in myself from last year and this year, that being i have met a lot more people. more people know who i am, more people come up to me at school. it makes me scared, because a large toxic part of me doesn't want to become close with them even though deep down i do. I remind myself that i distance myself because its for the better; my studies are better when i am alone, knowing more than one person stresses me to the point that i cant think or concentrate on anything else. Ive collected my thoughts before on paper, writing all the reasons why having friends is a burden. Is it bad that ive made myself believe having friends is a burden to myself and my achievements? am i just a terrible person who pushes people away because it distracts me from the future?