Camera on my laptop isn't working any more.

Can you do a system reboot (should be in the settings bit) which will restore it to a point in time when the laptop was functioning properly?

Try this video of how to fix a Lenovo laptop camera:

www.youtube.com/watch?v=d_hucSz3mQI

Could be an upgrade to any software, operating system, drivers, etc.

Hard to say from the info given in the OP

Have you updated drivers at all? There coukd be a problem with the camera driver.

You may have a virus. You should run a full system scan. Also make sure you have installed any system updates. This sounds like something more serious than a camera fault.

My mother-in-law has a clip-on-camera now for when she zooms. Her camera is defunct according to my son who kindly spent hours on it.
She doesn't have the "jumping about" thing though.
I expect it may well need replacing but might be worth calling a repair person for info and potentially fixing.