About plotting down the melodies

I wonder: I started composing by singing the atmosphere and then trying to find the melody on a keyboard. But as I composed outdoors pieces about the spring and wondered which note was which height, the birds in the trees sang what I wondered was as a note but those were by the atmosphere, by the style of the height, so they were somewhat like chords are supposed to be plotted down. So I do not know if this way of composing is right or should the notes be chords, should they be melodies made of the same or similar chords?
Ot is somehow difficult to play one's own melodies, maybe because one was thinking of recognising heights in the atmosphere and rough lenghts with style, and not of playing when one wrote the melody down. I once wrote again a melody and it become much more like what one can play or sing.

15.3.2020 I am not sure if this method of recognizing the notes is right but at least it is easy and produces melodies that convey the phenomenom they were about. But the original method of just singing soundedmore natural. https://learntalents.blogspot.com/2019/03/singing-spring.html But this method is good also if one does not have a recorder or an instrument good for this.
The lenghts I estimated by the lenght of the atmosphere tone and by it's impression: short is 1/8 note, ordinary lenght is 1/4 note, inviting, temptating is one and a half time note, for example times 1/4, long note is half note and a very long note is full note.
Chords go via practise: what is the upmost tone, how does the lower tone sound with it, which height is it? And via this practise also chords of three notes consist of more familiar sounds and are so easier to plot down.