I moved out of my parents house when I was 21. The only reason I stayed so long was because I was saving money. I'm close to my family but it wasn't really that hard to leave. I live only a few minutes away from them, so it's not that bad.
Even if you do find it difficult, it's an important milestone in your life. Learning to be independent is scary, but realizing that you make all the decisions in your life is exhilarating. Enjoy it!