The 3rd gear and overdrive went out on my 1996 Chrysler Sebring LXi Help?

yes it went out i have been keeping this car up for some time now everything was good i need to know how much it will cost to fix this problem and what i would need to buy to fix it im a girl who dont know much...can anyone help? i need my car asap and anything you could tell me about my problem would be so helpful