Lost video

I have been using zoom successfully for more than a year but about a month ago my video started being "flaky" & I would constantly have to keep clicking on the icon at bottom left to keep my video feed live.  Now the icon has disappeared completing & the only info available to the right of the microphone (audio) icon when I click on the up arrow is for speaker options.  Nothing on the tool bar to indicate what happened to my video!  Having been joining mtgs by audio only with a black box which includes my name.  Thanks for any help!