Nice capture. I copied your file and made the two image files from it.
The three panel image called channels.jpg is each of your channels separated out. As you will see, your red channel is completely saturated (white).
Choices are -
1. Use the Ha leakage into the green channel to make an image which I have done in the second attached file called green ch.jpg. I took the monochrome green channel image and artificially coloured it.
2. Reduce your exposure to capture better detail in the red channel
3. Do both - a high and low exposure. Then combine the red channel from the low exposure with the green and blue channels from the high exposure.
