Root cause of your issue is mysql connection limit:
[<a href='mysqli.mysqli'>mysqli.mysqli</a>]: (HY000/1040): Too many connections in /home/isalna/public_html/qa-include/qa-db.php on line 66
If you have root access of your server, you can increase the mysql connection limit by editing mysql configuration file. If you are on shared hosting, you will have to contact your hosting provider.
- Kailash