I went through IVF treatment to get preg. but it didnt work out..im so devastated and im cryin all the time?

cause the doc. has made me dream.. A LOT...he told me that it would succeed 99%..cause everything was perfect + im still young..23 ... im so worried now! since everything looked great why it didnt work? the nurse and the doc. were very surprised when they found out that im not preg. they were like NOWAY!! im so scared now..and im in so much pain..the whole process was extremely painful!! why did it fail? what do you think? im about to lose my sanity! ive been tryin to get preg. for about 3 years..i went through fertility treatments for about 5 times..and everytime they said you are perfectly able to get preg on your own! but it didnt happen...even with the treatments..it didnt!! im so worried!!! whats wrong with me?