My Penis Does Not Goes Inside My Partner's Vagina...we Have

My penis does not goes inside my partner's vagina...we have tried a lot but it's not happening ..we also tried lubricating the penis and used a smooth condom but still no result...sometimes it feels that it goes a bit inside but their is no pleasure and their is no fun in the intercourse and a bit means about only one fourth of my penis.Could u please help me out doc ??