Calm down not to worry its normal some time b coz its all in mind when you get more excited you cum fast pratice go slow try diff positions so be confident think you will do best things this time and trust me u will i said na its all in head man go n try & while doing do a lots of foreplay use ur tongue and fingers before intercourse eat healthy quit smoking & drinking and exercise a bit daily..it will help you 100% believe me...good luck man.