Your worldview is bursting apart because it is based on presuppositions that can't incorporate the new information that academic study is providing you. First of all, severe distress is a normal reaction to a worldview collapse but you need to try and keep your wits about you so you can reformulate a "larger" worldview that can cope with the aspects of academic study that challenged your old worldview. Secondly, you don't have to stop being a Christian just because your understanding of Scripture has been challenged.
One problem you're having is that your emotional reaction is magnifying the issue beyond what it really is. Saul, David, Solomon, and the prophets all most likely existed so you've gone way too far with the historical problems that a Christian has to face. Many critical scholars would back this up including Baruch Halpern, Robert Alter, Lawrence Stager, JD Schloen, Edwin Thiele etc. Robert Alter's work especially is a good starting point as it provides a necessary pushback against the unfortunate scholarly tendency to fragment and splinter things. Thiele's chronology as updated by Rodger Young also creates a good "frame" for the history of the kings.
Additionally, if you look at the narratives that scholarship has created you can read these as perfectly consonant with the Christian narrative. One of these would be the idea that Deut 32 is an early text of "Biblical religion" which evolves through Ps. 82 into monotheism in 2nd Isaiah. Actually, it's much easier to go from Ps. 82 to Daniel 7 with its Two Powers binitarian perspective and then into Mark 14 and the Sanhedrin trial of Christ. I've written on this here:
https://australian4pt.wordpress.com/2018/10/19/traditionalism-and-traditions-in-scripture/
Also, I suggest you look at René Guénon and his work to take things to a meta-religious perspective before zooming back into the story of the Israelites and the New Jerusalem, the Church. Again, what I wrote in the above link is a little primer to that perspective. Guénon's challenge to the modern world is worth looking at before you discard one worldview only to find that modernity and postmodernity have nothing stable to offer you to replace what you've discarded.
Feel free to PM me for a chat it you need it mate.