I'm a composer. I think it's great that you have an interest in composing your own music. However, I would encourage you to develop your musical thinking so as to combine multiple melodies at once. This will make your music more harmonically and stylistically rich! Right now, your style is a bit too limited in terms of compositional technique to attract much attention. It's great to be self-taught, and many of the great composers were mostly self-taught. But you must learn to be a great self-teacher, and that's not an easy thing to do. It would be very helpful for you at this point to play the music of other composers, in order to expand your musical imagination and broaden the horizon of your musical taste.
By the way I learn in a conservatoire, but there I don't learn anything about composing.
Thank you for your andwers awesom_o and dcstudio. dcstudio, today I will tell my teacher, to explain your words for me, and I try it , thanks!