==Then why is the prospect of a 4.5 billion year old Earth so hard to accept?
Because it contradicts God’s word. Although, I must admit I find a six day creation far more impressive than 4.5 billion years. Can you imagine if Rome actually was built in a day!
Then you don't believe all things are possible. Only those things that don't contradict your reading of the Bible.
No, it contradicts your ego-centered misinterpretation of His Word (which is absolutely true).
If you knew the omnipotent, omniscient, omnipresent, eternal, timeless Creator Whom I worship, you would be amazed that He bothered to share with us that his design, creation, formation, direction, development and maintenance of His universe took any time at all. Instead, you insist on cramming your shrunken deity into an earth-limited timeframe that your mind can encompass -- despite the manifold witness of His majestic Creation:
(Click on this image of a miniscule fragment of His Creation for data that shames your Ussherian confinement of I AM into your Sistine ceiling image of Him.)