I've been there; these sort of episodes of anxiety used to really cause me to become obsessive. You think your thoughts and fear is silly.
Well, I used to think about what if people can read my mind, and just don't say anything. Things really got scary when I would be talking with someone and they just so happen to bring up something I was thinking about. I used to really fear that people thought that I was a creep and crazy, because as a human being we all have different thoughts about different things, the good thing is those things are only thoughts and do not exist in reality.... however, when you are suffering from GAD like us, we bring those fictional and pathetic thoughts to reality although they aren't real. When I tell you that I have been through every single thing with my anxiety.... I mean I have been through things that was just down right pathetic and I am afraid if I share some of those stories they will probably lock me up in a psych ward. Honey, after battling anxiety for over 20 years it lead to depression, ocd, health anxiety, and panic disorder... I knew that I had to take control of my life, there was no other option. I have been dealing with this since I was 17 years old, and I am now 38. I cannot tell you why GAD occurred, but it did, and it happens to the best of us.
I eventually put my foot down, and fought back. I overcame the irrational thinking, and fear. I am now back on track, although I do still have my episodes but now they are controllable and I am able to have self-control. Don't get me wrong the medicine and the therapy was a big help, but they were just temporary fixes and I knew I had to do more to gain self control.
I actually read a lot of self-help books, that has helped me a lot and fed me with so much motivation, and although I pretty much outgrew my anxiety, I still find myself in a routine to keep the motivation and wisdom.
I actually just purchased a book called "Anxiety Street: GAD Self-Help Techniques" on amazon.com, its not that long it is only like 11 pages; however, the motivational section of that book is priceless. That's the most current book I purchased. However, I have tons of other books that has helped me.
Try reading and feeding your mind with real life stuff. You can overcome these thoughts.
Good luck hope I helped.