This story excerpt is courtesy of our partners at KHOU 11. Click here for KHOU's full story, and click here for more coronavirus coverage from KHOU. HOUSTON — More than half a million Texans have filed unemployment claims in the last 18 days due to COVID-19, according to the Texas Workforce Commission. Texans have documented their struggles of trying to file both online and over the phone. "This unprecedented increase has led to long wait times, overwhelmed call centers and technical issues…