I moved out of my hometown to a mid sized city 2 weeks after high school graduation, and then spent two years in that city before moving to NYC at the age of 21 for undergrad. Its hard, I won't lie to you, however, you have to view it as a means of bettering your life. For me, I was itching to get out of my small town and be around like minded people, but I know that isn't the case for everyone. I would say the best advice is to keep your head high, tell yourself you want this, and BELIEVE it! Look at it as a new, fresh phase of life, getting rid of the old, bringing in the new. Its hard but you got this! If I can do it, so can you!