I am sorry to hear that you are encountering this. What is most likely is that there is another process trying to use yum to update or install packages. Can you please give me the output of the following command on your server? ps auxwwf | grep yum
Please note that sometimes this error is only temporary so you may be able to try again shortly.
The error shown in the screenshot you provided in your last update is unrelated to the error in the original screenshot you shared. You can try to find the PID of the process holding the yum lock by running the following command:
It is possible that the process is no longer running, but yum has remained locked. In this case you could delete /var/run/yum.pid to remove the lock, however I would suggest you have your system administrator review the issue further as this could indicate other stability and performance issues with your server.