In relation to your cervix and vaginal walls, please, don`t worry, having normal sperm quality and regular intercourse is enough for sperm to find their way to the egg. Please check if you had tests like fallopian tube patency test, ovulation test (home ovulation predictor kit and progesterone blood test a week after ovulation), Vitamin D level test.
If your partner`s age is over 45, or maybe a smoker or diabetic, or having other significant medical condition, I would recommend sperm DNA fragmentation test as high fragmentation level can significantly reduce pregnancy chances.
You may benefit from reading about lifestyle: Rebecca Fett: It starts with the egg.
Please note that the only effective treatment is IVF, and IVF chances do decline rather quickly in your age and with your given egg reserve.