My experience is from travelling in Central Europe and Germany, so I've dealt with much smaller amounts of money, but the general principles are the same.
Many Visa-brand ATM cards allow you to withdraw money from European ATMs for a 1% fee (plus any fees the bank may charge, my bank charged zero fee) in local currency. Even if the bank charges a 2-3% fee, the combined max 4% fee is going to be a lot smaller than most currency exchange places will offer. There are a lot of exchange offices that are built to scam tourists out of their money. We had no choice but to use one that ended up taking around 10% of the exchanged money (luckily we were only exchanging a small amount of currency). Call your bank and ask what their fees are, and if they are large, find a bank with small or zero fees and move your accounts there. Be sure to notify your bank that you are going to be travelling for an extended time in a foreign country. Literally any ATM (Geldautomat) accepted our card (thank you VISA). We literally walked off the plane with some USD and no foreign currency, and were able to stop at an ATM right outside our hotel (the taxi had a card reader, as most in Munich did).
If you have a source of income secured within the country (which I am hoping you do if you will be living there) you could live off of your income, and use your USD to pay off things like credit card bills. Get a Travel Rewards Credit Card (or similar card that offers no foreign transaction fees or free currency transfers). Use this card for anything and everything you can, and pay it with a transfer from your US bank account. Under this method you'll probably have to convert some currency, but you can do so from an ATM easily enough.