Editting can be very frustrating in my experience.
And yes not being able to save the work done when it has taken a long time adds to the negative feelings.
I finally realise that I can cut and paste the Track info into a text document.
And take a screen shot of the first Release info page.
Which will save most of my work but not refund the time.
Editing does get easier with practice. Though a few months off and it gets more difficult.
If you can provide screenshots then us volunteers here will almost certainly get things solved.
POST is a HTTP request method which should be used to submit the web form with the data you want to seed the release editor with. Have a look at the source code of the seeder example and you’ll spot it: