Am I going crazy??šŸ˜­

So Iā€™m 17 w health anxiety and today has been pretty bad dealing with my anxiety symptoms. I was at work sitting in a chair and my friend was sitting beside me in another chair. My friend moved her chair but when she did it felt like someone was moving my chair but no one was. It was just me. And I did a huge jump/jolt thing cause it scared me and freaked me out. Iā€™m seeing a therapist soon but Iā€™m so worried somethings wrong w my head like a brain tumour or some weird disease. Help me.