Q: What can make penetration less painful?

Oooh! "Less painful" is a difficult goal; I'd like penetration to be pleasurable for you!

I'd like you to start with a thorough exam by a gynecologist or someone who specializes in women's health. If the problem is vaginal/vulvar atrophy, then localized estrogen may help to restore some moisture and elasticity. What you describe could also be caused by vulvodynia, which can cause burning sensations and pain with penetration. Again, a healthcare provider experienced in treating mid-life women can help you evaluate options.

If atrophy is profound and longstanding, you may find vaginal dilators helpful, too, in regaining caliber--the size of the vaginal opening.

I do hope you'll investigate--and raise your expectations. The minimum you deserve is no pain; I know you can have enjoyable sex again!