Will I ever get along with my cousin again? Please Help!!!?

I have a cousin called Elliot and he is 10 years old now. Im 12 years old and hate his guts. I know it happened 1 or 2 years ago but ever since I just can't seem to forgive him! It all started when his mum, him and his brother invited me and my sister to the priory marina and we were fishing for tadpoles. After wards, his brother, his mum and my sister were looking at a river over a bridge while me and Elliot were waiting at the car. He said he just wanted to get home because he was cold so he picked up a twig and put it in the car lock to try and open it so that he could wait in the car but it broke and got jammed in the lock so when his mum came she couldn't open the car door! He blamed the whole thing on me and he told his mum that I told him to do it and his dad shouted at me!!!!! Luckily my parents believed me and in the end my dad got it out with tweezers but I have still not been able to forgive him!!! What should I do??????????