Hi poppet.
I completely understand how you feel!!
I had a scan this time last year which showed a huge cyst on my right ovary, but it just disappeared on its own, with no issues.
Had a check up last month and still clear.
I know it's scary, but it's good that they've found it and can monitor the cyst with regular scans to check it is shrinking etc.
Lots of info online about cysts.
Good luck