Don t feel terrified at all. It will all become normal in a few weeks. Think of it as an adventure, you get to see how it s like living in Washington. Many people move each day, some from Texas to Florida, others from Florida to Illinois, Others from Illinois to Washington. It happens always. Many people wish to move. Think of yourself lucky, you get to have large mountains nearby to visit, and hopefully snow close by. A typical Floridian would love to live in Washington, that s where they all travel for vacation. The same is vice-versa with all places. Just go to school with like you did in Texas and it will be all fine. Instead of thinking about worries, think about what good view you may find out of your classroom window. Good Luck
Be yourself and you will be just fine. You will make friends within a few days. You will adapt just fine