I understand. If you can't get approved for much under FHA which is pretty liberal, I can't imagine many owners wanting to take that risk. Also, properties under the 250K range are pretty selling quickly.
You need to review your credit report. Go to www.annualcreditreport.com and get your free reports. Review why your score is where it is and work to increase your credit score. Ensure your monthly payments are made timely and work to reduce any balances below 50% of the credit limit. If you have any collections/judgements/tax liens, be sure to get those addressed.