Trust in your own abilities and use the skills that you have. This is how you will lay the foundation for personal and professional growth.
Embarrassment is often a result of fear; the fear of making a mistake. If you treat mistakes as learning experiences, then your sense of embarrassment will be lessened. It isn't easy to train yourself to embrace mistakes, but you can do it; and you'll be very glad that you did.
If two products are very similar, it's the small details that make all the difference. Don't neglect the small details; they could be your advantage.