I'm scared I have Sporadic Fatal Insomnia.

Hello! For about the past three days now I have had trouble sleeping. I get maybe one or two hours a night and they aren't super restful or very deep. I am 18 years old and have anxiety, so I know that I have fallen into a cycle of dreading not being able to sleep and thus not sleeping. Benadryl did not help, and melatonin helped me stay asleep for six hours last night but it wasn't very deep.

Last year when I was having a similar bout of insomnia, I made the mistake of coming across sporadic fatal insomnia on WebMD. Since then, whenever I can't sleep I start freaking out about having SFI. I know that I likely don't have it, but I need the reassurance. Is it true that the insomnia part of SFI is misleading because the insomnia only sets in once you go terminal? If I did have SFI would I really be in no state to be typing this? Thanks!