Is it normal i want to have sex with my "ex" boyfriend

i had been dating this guy and we only met up once, when i think about it i get so depressed, anyways we only kissed never got to really see him again he is sexualy attractive i think, and ive known him now for about 6 months, and its like i crave for him like i really need him, just need to see him one more time and then thats it :( , we dont talk anymore hes deleted him recently and is intrested in my friend, so i dont know is it normal that i have sexual feelings for him ?