how to disvirgin a lady

i shld be called “girls follow me”..cos of my long dick,they cnt just stay away from me,,,i met a virgin and now we are dating,i love her soo much,but i have never disvirgined a girl before,she allowed me do it,but my dick could not get into it…i love sex alot,and i dnt want to cheat on her….i have tried on several occasions but just didn’t enter it,i advised we go to a doctor,but she said she want me to do it…..am tired of trying….but my body needs it…pls how can i go abt it???….