Composing is a Craft - make it a habit
While talent is certainly part of composing music, skill and dedication play a large role.
I've talked with numerous composers about "how they work." More often the younger composers, not in terms of age, but in terms of years composing, tend to think of composing as 90% inspiration and 10% effort. "If I'm not in the mood, it just doesn't 'come' to me," or something of that effect.
Don't discount the need to work it every day to keep those skills sharp
My advice: change your attitude and approach; you'll do better in the long run.
The initial phase of making composition a habit is to select a time of day when you will sit down and compose. Then, every day sit down and compose. It may start with reviewing a few of your recent projects (yet to be finished), or going back to some really old things you haven't looked at in a while. This can be a great way to clear your head from the maelstrom of unrelated thoughts and get it thinking about music. Another option is to select a scale you like (or something obtuse) and "improvise" a theme over it. The point of this opening exercise is to get you thinking music in a more sub-conscious way -- letting the inner music bubble to the surface. You shouldn't concentrate too much on whether the music is good or not, just immerse yourself in it.
After half an hour of this kind of work, put it aside (unless it has sparked something that you can't put down and feel the need to finish). Think about what projects you have to complete. If you don't have something in the pipe that needs done, create a project, choose an instrument, a performer or a topic you'd like to write for/about and start working.
Composers work in a variety of ways. Yours may be to research all the various techniques ans specialties associated with the instrument before you can begin actually writing something, or determining the scale, pitch class set, tone row, or harmonic progression you're going to use. Either way, start making those decisions. Don't wait until it 'feels' right; just do it.
Get into the habit of starting your musical day this way every day. Don't think of it as a job, but do think of it as a craft, something that requires work, effort and dedication to accomplish it. By working it every day, you'll quickly find the 'inspiration' comes more readily.