1. Stop using turns
2. Disband all fleet
3. Sell items on market
4. Check important events to tell if things are sold
5. When they sell log out and back in
Reasons
1. Using turns will ensure you keep increasing your debt through both upkeep on ships and debt interest
2. As above stated ships require upkeep per turn, watch your future spending by clicking on income and seeing where you spend.
3. Sell enough items to bring your cash back into positive.
4. This is so you don`t need to use turns you can refresh you events page to keep a eye on items being sold, can also click on important events and click on refresh (F5) for this
5. The logging out and back in will refresh your figures correctly.
If after this you still find yourself in debt and unable to recover you will have no choice but to restart. Go to Options, Restart Empire to do this.