I've had friends who did a fair amount of commercial music to make ends meet. They would submit dozens to a hundred submissions for each thing that got accepted.

The people who asked you to do this are doing it wrong. They just wanted music and thought they would find what they wanted easy and cheap without sitting down, thinking hard about what they wanted and finding the right person to match their particular taste.

The guy who is right for one project is often not the right guy for another. They might not have done this often or thought very hard about fitting the right music to their vision but I bet they are learning a lot about the process at your expense.

There was one guy I knew particularly well. I knew him when he scored his first documentary and I knew him years later when he had done many. He was sweating his balls off full time when he did the first one. Later in life, scoring a documentary was something he fit into a busy full time studio schedule.

The thing that probably made him the most money over time was getting a song from one of his first bands on MTV road rules. He was getting checks ten years after it aired. He never even submitted the song to anyone, they just asked him to use a song from his band that almost no one had ever heard of that he made when he was 18.

Other times he would record a dozen submissions for a Rice A Roni commercial that he really thought were going to be the thing and and stare into the void of indifference. A week after that Northrop Grumman would accept a few tracks to go over military equipment sales videos.

Fitting music to video isn't as easy as asking someone to do it. I hope you learned a lot by giving it a try, learning is where the real value is in this kind of thing if you haven't done it before. You weren't exactly set up to succeed and you shouldn't take it hard in anyway what so ever.