Don't know if this may apply to you, not knowing where the sensation of walking on golf balls is.
I had the experience of feeling like I was walking on a stone under the ball of the foot - but also there was a lot of pain and I knew it originated due to grinding sensation in the bone area under 2nd toe while playing tennis.
Xray ruled out fracture
MRI rules out neuroma
Final dx was predisclocation syndrome - the bone in the base of the toe on the pad of the ball of the foot was subluxating - dropping toward the ground.
Unfortunately for me, conservative treatment with ortho shoes and ultrasound did not work and I had a "hammer toe" surgery to "fix" it. I ended up with crps.
But - that is me - not you. How long have you had this, and has anyone evaluated it for you? Where is the sensation and is there pain with it?
Hoping you can get evaluated and treated. Not being able to walk is definitely a big show stopper.