Justified Psychosomatic hypocondria

I'm new to this site so HI everyone!

Although I've not been diagnosed with hypochondria I'm fairly sure I have it, I bare all the hallmarks of a hypocondriact. I used to worry about brain tumours as a child, had really bad anxiety as a teenager Etc. Over the last few years I've really started to worry I have dementia (I'm 25 by the way) I know I'm a bit young to be concerned about loosing my mind but a form of dementia runs in my family. My mum's got it, my uncle's really ill with it and my grandma has died from it. Now I keep convincing myself I have it. Even though it's very rare to get it at my age. Every time I say a word wrong or move slightly weirdly I think I have it, then I start to think about it over and over till I'm totally convinced. My question is, has anyone else ever had health anxiety about dementia and what physical/mental symptoms have you had ?
Thanks!