I was always an a+ student.why do i feel really bored at studying? i've tried using colors changing place. writing.also studying for 45 min n 10 min break it worked for a couple days and and now i feel like i hate studying again.

Hard to say: Some would label this "burnout" but it is hard to speculate on so little data. The stresses of being held to a certain standard can place a drain on anyone. You may need to seek out a life coach/therapist to learn how to deal with the issues involved. Your regular doc may know someone locally to refer you to.

Good eval: Sounds like a good basic psychological evaluation is indicated, perhaps you have been able to compensate and now that yu have to study your attention symptoms are showing up. Start with removing additives and hormone disruptors , toxins from diet and environment , optimize sleep, 30min exercise /d min. Remove inflammatory foods , sugar, dairy grains. Consider medication, good PCP eval and labs