"in order to fulfill the prophecies, he had to be born of a virgin."

He seems to have fulfilled all the other ones without question. Are you really withholding faith based on the potential that maybe this one prophecy was fudged? Have you gone back to the Mosaic prophecy to fully translate that one as well? An important undercurrent throughout Jesus's teachings is that the Spirit of God and God's law always is more important than the written letter transcribed, interpreted and understood by man. This might be a case of investing your ego in the debate more than satisfying the needs of your heart. Debating and questioning one's beliefs is good practice, but there is a point in which you must admit that "for those who believe, no proof is necessary; for those that do not believe, no proof is sufficient." Agreeing to disagree is always an option.

Not every point can be proven, and even when Jesus was physically present, He allowed people to doubt Him and deny God, although He warned against it. If proof of God and Jesus's divinity were on display in a museum, our faith would be moot. In my experience, God gives us leeway, and we can always choose to doubt. It doesn't mean we always should.

It is easy to find voices on every side, for every verse in the bible. But the answer for a troubled heart cannot be found by poll, argument, or even a lifetime of Greek, Latin and Aramaic studies, as the conflicting translations demonstrate. If this question truly troubles you, I advise praying on it.