Preoccupied wid distressing thoughts alw

I am a medical student:post intern...in clg two years back i had issues wid my friends...since den i am unable to move out of it...i keep thinking dat i have done something wrong to dem...i am wrong ..i have talked to dem nd dey say everything is ok..but i am always thinkind about d same...i am unable to study since dem...my academic performance has decreased a lot nd i have gained around13_14kgs of wt..talking to anybody distresses me...i feel again somebody will feel bad of what i say or something new will cum out dat i will feel i was wrong at...i have my pg entrance exams but iam just unable to study...i deleted my social media to avoid everything but of no use...i keep thinking d same...my parents say i should focus on my exams nd health..i get motivated for a very litle tym nd again sum distressing thoughts..how should i study...mjhe is topper jaisa bmna h uske jaisa bnna h bs yahi soch k din khatam kr deti hun..fir sochti hun us topper k koi frnds honge nd bs din khatam.ho