When i put my inside my wife virgina, she feel paining some time not going inside,plz helpe me?

when i doing with my wife, when i put my inside her virgina, its paining for her, some time its difficult to go, if i press and force she feels paining, but before that we are doing play, kissing and i am tried to increase her feelings. some time i put my fingers inside her virgina before , that time she is getting good feelings and enjoying, but when i put my inside that its paining for her, some times it wont go inside, please help me and i want to give good satisfaction to my wife without any paining.