Having a feeling of dread is a very NORMAL and COMMON side effect of Anxiety. It doesn't need to be connected to anything, it's a sticky awful affliction and doesn't go away easily. So is loss of appetite, I have that myself, and need to set eating reminders half the time. This is all your mind playing tricks, I promise.
I want you to take a long deep breath, and trust me; You losing your license has nothing to do with anything, it's a coincidence. Nothing more, and no reflection on your state or your health. You're thinking this way just because you're feeling anxious and that can have a very real chemical impact on your body. It's your mind playing tricks, don't let it. Share your feelings with your friends and loved ones, in my personal experience, this helps a great deal.
If you're worried about drinks, try to ask yourself why you think this way. Really think about it, critically. Why would these be poisoned? Who could possibly do that? Nobody. You're safe. If it's really bad, than for now, drink stuff that's been bottled. But please try to keep an open mind. I know that's hard, but it'll be worth it.
You'll be fine, your worries are understandable, and you aren't alone. Try to do something that makes you happy.