Can't find library contents

I have just renewed my account and it made me download and set up my account and download the player again.

now that I have my account again I now can’t find my library with my downloads and it keeps asking me to download the media player again.

Everything I try it keeps asking me to download the media player and I still cannot progress further.

I have been a happy member using Plex for the last 2 years but now I can’t seem to get it to work as before.

Please help so I can get back to using it again.

Does that mean that you are using now a different plex.tv account than you were using before?
If that is so, then your server is still on the old account and you need to change that:
https://support.plex.tv/articles/204281528-why-am-i-locked-out-of-server-settings-and-how-do-i-get-in/