I've changed my major 4 times at least. and I have been in college for 5 years with two 9 month breaks. I have 3 years left of my undergrad, and then there is med school. I understand so well.

Think of things this way, will you be happy with your chosen field? Happiness is the only thing that matters. I have felt like you feel, and then some. College is hard, Life is hard, Changing where you life is hard. But don't forget about all those that you can meet in the months to come, the people you can help, and those that can help you.

Think of the good things, and then think of some more. It will be hard to live on campus versus off, but one good thing, you don't have to take to much time to get to class. Stay positive, that's the best advice I can give you.