Hi Gregg,
Production music is a numbers game. The more music you have out there the better your rate of return. I would suggest to start off by also having instrumental version of your songs and submitting them to libraries or directly with music supervisors who are looking for your type of music.
The amount of money you can make REALLY various. I’ve heard of folks making enough to live off of their music with a catalog of about 300 tracks. Yet I know people with about 1000 tracks that are making just enough to supplement their day job.