Try avoid Google as much as you can, one thing I learned was that if you keep overthinking pain or sensations in a specific area, try focusing on a completely different part of your body (eg big toe) for 2 minutes and eventually you’ll notice all different sensations etc, that don’t bother you, this can help you understand that sometimes it’s just the way the human body is.
Another thing is that pain like headaches, can be caused and worsened by stress, so if you get a headache, take some painkillers, drink some water and stay off the internet for a bit. Most headaches are caused by dehydration. Health anxiety can be super tricky, but you must try and challenge your thoughts, ask yourself ; what evidence do you have that disproves this?. When we hyper focus on one condition or illness, it’s easy to find lots of evidence to support it, despite it being a false thought.
There’s LOADS of self-help guides and information online for health anxiety, using cbt techniques, definitely worth checking out xx