Waaah!! 
I need sooooooomeone to pay attention to me or I'll just die I tell you. 
Firstly, your "Waaah!!' graphic, attached below.
Then:
000.) Often enough, unless you are Mozart with all his very early advantages, the beginning composer has to accept that their first / early pieces will not be perfect, will not be everything they intended and wanted, and that it is necessary
to have the experience of making a beginning, a middle and an end. Beginning composers need to practice that just as beginning instrumentalists need to learn how to play scales, up and down! Short and shorter pieces are the initial practice steps, then increased in scope and length as one develops the experience and skills from the experience.
Nextly:
1.) When you're stuck, leave a blank gap, and go on to the next part you are more certain of and write it down; then you at least have 'where it came from and went to' to give you a better idea of what goes in the gap section.
1.) When you are stuck,
write in just about any old thing, because often enough knowing what you do not want helps you figure out what you do want. Choose some notes, configurations; they're just notes and configurations and you can change them.
1.) When you have a plan,
you at least have something to deviate from. (It seems you have enough down that what is done so far can be considered 'a plan.')
1.) As the number of pages grows (they should be notated horizontally, not vertically) make a copy that you can tape up, left to right, on a wall. Seeing it 'all at once,' and reading through left to right can be enormously helpful.
0. (and 1 through 10.)
An eraser is your best friend. {
See second attached image, below.}
Always best regards.