Hi and thanks for your post

It's good that you have a chance to go over things with the GP - though it can be helpful to make a list of questions as it's easy to forget when you are on the phone.

No one here will be able to say what this may be, and you can't really compare with anyone else as people will have different experiences . If it comes and goes though,  it's possible that it may be related to hormonal changes or that it's a cyst which is pressing on some nerves. It's also possible that if it was anything serious it would be less likely to disappear, but I can't really say . You can also ask the GP for  his thinking as to why they think it may be a cyst as that might reassure you. 

If you feel your anxiety is getting worse do have a chat with them about this as well, as it's possible there may be some local help with this. The following website Every Mind Matters about coping with anxiety may be worth a look at 

Try and not over think things and I hope things settle down for you

All the best

Wanda