I can absolutely relate to your fear. I for one have yet to make anything larger than a lap quilt or crib quilt. (I am afraid I'll get bored and never finish it.....)
Find a piece of fabric that speaks to you (you just absolutely love it!) and make a small project: a potholder, a runner. And (this is important), pick a block that you feel confident you can be successful with.
Do not, do not, do not something that exceeds your skill level right now. Some of the people on this board (who make the most extraordinary quilts) have been perfecting their skills for lots of years.
Most important, enjoy the process.....