Inhibition towards composing is an entirely psychological thing, I think. If you start out wanting to compose complete pieces and feel intensely dissatisfied at your very first efforts and then quit, obviously you are not going to make any progress.
If, however, you make requirements of yourself significantly lower than "I want to compose a Mozartian sonata" (not that you did, that was just an extreme example) and allow yourself to be satisfied with your first efforts, i.e. taking satisfaction in whatever music you write being YOUR OWN, you will find it much easier to stick with it. Take the attitude that it DOESN'T MATTER how your music stacks up to even an average composition. Try to focus entirely on feeling joy at just making your own sounds.
This is all easy advice for me to give, because this happened accidentally for me. I got into improvisation (which is essentially instantaneous composition,...I rarely write things down on paper, and it is much more fun and less tedious than composition) through listening to what most Classical musicians think of as extremely vulgar and base music: Black metal. Some black metal bands have classical like dark sounding arpeggios in the keyboards. When I started out, I wanted to imitate these sounds. They consisted mainly of minor, diminished, augmented arpeggios, but it gave me a great start in keyboard harmony and playing. Because all I wanted to do was play these simple arpeggios, I had NO inhibition in learning to write my own music. Then, psychologically, my brain made a gradual transition between these easy dark arpeggios and trying to imitate classical music. I had additional influences which helped set me free (such as finding a more experienced improviser/composer to encourage me), but I think that initial psychological state I was in was crucial.
Topic: The secret of composing???