I've suffered health anxiety for 2 years after I got misdiagnosed having a heart attack.

Started getting better then I caught covid. 3 months after covid I started getting hive like rashes and loosing my hair this has been going on since September. Sometimes I get hives but lately it's more like skin writing when something brushes on my skin it causes welt type scratches. I saw a derm he gave me more antihistamines I have an app with an imunolagist in Sept. But im so scared its skin lymphoma. Intake antihistamines everyday but onde I stop taking them I'm itching like mad. I have no other symptoms. My hair has started to grow back also. Has anyone gone through something similar