Hi dear, See as per your father's perspective he is not only stressed about your past attempts gone wrong but also he is worried about you...Also you have the full right to pursue your dream...So I advise you to talk to your father and  mother about exactly why you want to give one more shot..Plan your preparations and reasons for your failures and show it to them...I mean there is always room for improvement..So you first be clear about the mistakes that you are going to avoid this time...talk to your seniors and those cleared it about insights...ok ..goodluck