Try sticking to one aircraft type until you have at least five of them. My guess is you are bring killed by maintenance costs.
You should also consider keeping away from the most expensive airports for the first six games months. If in US don't use any airport where gate costs £100,000 or more to start with.
WELP! That failed! ! I started at a US airport because I thought it had good business. Can you help me? By like, you know going into my account and making some changes and whatnot? I can add you if you want to my airline for a while so that you can edit some of the options I have set.