This is a very general question. I would need to know much more specifics. Profitability is based on:
1) The keywords that you are buying 2) The negative keywords that you have added 3) The CTR of your ads 4) The ROI and setup of your landing pages
The best way to turn Google AdWords around is to start learning more about it from experts that have been doing this for year. In fact, we just launched a new guide here that you can read more about. http://www.adwordssystemexposed.com/
If you have more specific questions please let me know.