I feel your frustration. I researched off and on for 8 years. My grandmother's maiden names had at least 5 different variations none of which was the true name. I also posted on here and someone responded and said I was looking for the wrong name. As it turned out I was! I worked with gentleman and trusted he knew what he was talking about.. he did. After 50 years of no contact I visited my grandmother's family in Lithuania in 2015 and 2016.
My point is don't give up and treat every clue as if it was its important