There are many possibilities here. If you change to barefoot, it will have you landing differently than shod. If you had problems shod, you may have different problems barefoot, since changing your style of running may not resolve other mechanical gait issues.
Question - do you have a short first toe? If so, you may have a neuroma. If your legs are generally tight, especially in the back of the leg or calf, it can cause you to impact hard with the forefoot, even though you may not sense there is something wrong.
If your core is distorted, it will cause you to impact hard on your forefoot as the legs tighten. Can you squat without losing your balance? How about standing on one leg, then the other for 30 seconds. Is your balance symmetrical? Do you feel stiff getting out of a seat?
These are all indications of core problems that may need to be addressed. You may consider reading my book Cheating Mother Nature which talks about body mechanics and it is written for regular folks like yourself. It may help you figure out your problem.
Another good suggesting, find a good sports chiropractor. Hope that helps.
Dr. C