I personally couldn't create a great work of art if someone put one million dollars in front of me, but that doesn't mean that if I was dedicated to art, I wouldn't try as hard as I could and somehow be involved in it. You are there for your religion. If teaching isn't your skill, don't give up on the church. Position yourself somewhere else in the church. Perhaps be an altar server.
Catechism can also be hard to master.
I have no trouble in my sixth grade class, and haven't gotten a problem or issue once. I like working with the DRE, and I have gotten nothing but support and guidance since the beginning. With my fifth grade class I do have some trouble. Some parents weren't very happy with the idea of a fifteen year old catechist and I did make a few mistakes in the beginning, which is definetely expected for a first year catechist, adult or teenager. I didn't get along very well with the DRE in that program either.