That's a tricky situation! While it's tempting to use third-party sites when Google Play isn't working, it's often risky. Those downloads might contain malware. Have you tried clearing the Google Play cache and data? Sometimes that fixes the issue. I understand the frustration though; I felt the same when I couldn't download a new car racing game. I ed up just playing
Drift Hunters online instead, which was actually a blast and saved me the download headache! Hope you get it sorted soon!