Internet icon is now missing

[Şerban S.]

[...] It also told me when I was connected and at what strength.

What you are looking for is the NETWORK MANAGER icon. The internet icon is associated with a browser, which is a totally different thing.
Unfortunately, I never crossed such an issue in 25 years or if it happened it was solved too fast to remember the incident.
Can you make a screenshot of the lower part of the screen? Specifically, the Panel 1 section?
The icon you are looking for is the one in my screenshot. The pointer is on the icon.
If this dissapeared, it means your Panel 1 has trouble. It seems it happened many times and it is XFCE related.

https://www.facebook.com/photo?fbid=3105917639456126



IF SO:

Right-click the TaskBar; Choose Panel, then Panel preferences....
Now, select Panel 1 and then the "Items" tab.
You'll see a list of some items. Click on the + button and add "Indicator plugin". Place it at the end of the list and see what happens.
It might show twice some other icons but this is something that goes wrong in XFCE and this is way above my knowledge to fix.
Anyway, you should see the Network Manager icon now.

Good luck!