Breakup ?

How long does it take you to get over a breakup ? Is it normal to cringe inside and cry when you think about them moving on and all the love and sex and affection he will give her ? For him to cuddle with her . Lol i know i hurt myself thinking that deep into it . Do you guys believe in bouncing back ? Me & him are 18 & 19 . Do you believe in we are met for each other but met to early . Lol idk . But i know the relationship is over we both love each other but things arent the same anymore . Its hurt me inside and idk what to do . Any stories or advice or anything is helpful .