Is it a good idea to repeat iitjee?

i messed up all my exams this year because i was distracted by my bf and i hardly studied. i got a score of 90 marks in iit jee and honestly i did not study for even 1 hour everyday (just before the exams i studied for 5-6 hours for a week or two). i dont think i have studied even half of the syllabus. i am thinking of repeating. is it good idea.? i have a dream to become aerospace engineer and join isro. if i dont repeat i wont be able to fullfill that dreaam and i will feel like i did not even try and regret it for the rest of my life ( i am regereting not studying so much now). but nobody can say for sure i will selected and get my desired branch. so is repeating worth it? if i repeat i know i will work hard and wont get distracted by stupid things. i will also be giving isat if i repeat.