Hey there,
I know how you feel as I can be up and feeling good in the afternoon and the next morning wake up with anxiety.
Anxiety, unfortunately, is something that can fluctuate, but there are things that you can do to try to contain it at a reasonable level. I say "reasonable level" because anxiety is a part of life and motivational psychologists tell us it actually plays an important role in helping us do the things we want to do. So, it's not all bad, but it's not all good, either.
Things can get better and they will get better if you begin to turn your thinking around. Concentrate on the positives that happened to day and don't get caught up in the "what if?" thinking.
Kindly,
Kitt