But I’m so uncomfortable with the subject!
Get over it. What matters more, your discomfort or the eternal well-being of your child?
A specific reason why many parents feel uncomfortable sex educators if they feel that they don’t know enough about the specific scientific facts. One particular thing to be aware of is that our culture tells us that we need to be experts in biology to do a good job about sex education with their children. This is a false idea. It is false because the most important lessons about sexuality are not scientific concepts from biology, but our moral concepts and relational concepts and how we live our lives. Do what you need to do to get ready, and dive in.