X axis too big - Resizing graph

Hey Everyone,

My graph has a huge x axis; which leads to an annoying horizontal line.The y-axis is not appealing too.
I imagine this is a simple issue, but I just cant find how to solve this issue.

Please Note: I know you all prefer excel files to work around yourself and don't typically like images.
But I hope you can understand:
- The file is too large to upload here.
- I don't know how to replicate the issue on a smaller scale. Since the whole spreadsheet is pretty complex

Therefore images are the best I can do right now.

The images show the graphs along side the options I have under 'select data' and 'format axis'

Thank you all for you continued support!

Confirm what I see in the pictures:

You are using a line chart (not a scatter chart).
There is noting in the horizontal category axis labels range, so Excel is simply using count numbers for each "category"/data point. What exactly do the numbers on the x axis mean?
There is only 1 data series. Is it a multi-area range scattered around the sheet, or one contiguous range?
The horizontal part of the line is does not represent blanks or zeroes or similar, as the horizontal portion seems fixed at ~8,000.

Assuming some of those are correct, some things to try:

1) Can you use a scatter chart, or are you required to use a line chart? A scatter chart will allow to set the max (and min) values of the horizontal axis.
2) Can you set up a dynamic named range to make the number of data points in the y values (and/or the x values) dynamic? This will almost certainly require that your ranges be contiguous rather than spread out, if that is part of your sheet. If you are unfamiliar with building "dynamic charts" using "dynamic named ranges", review something like https://support.microsoft.com/en-us/...-range-in-exce
3) If your Y values are spread out, can you rearrange the data (or a copy of the data using lookup and other appropriate functions) so that the y values are contiguous?