I created this spell to help my wife who suffers from anxiety attacks usually late at night when she wakes up worrying about money or the kid's exams or suchlike. I have no basis for any of the components used, just that they seemed right at the time that I thought of it.
Using your athame cut a length of bramble 2 or 3 ft long. You will also need a square of cloth (preferably black although I used some old jeans of mine) about 18 inches square and some salt.
Cast the circle and perform your own grounding ritual.
I asked for help from Branwen as I felt she might understand these problems but you can call on the deity of your choice.
Knot the bramble into a circle and place on the cloth.
Walk round the bramble widdershins and at the first of the four directions cast some salt into the circle with some force saying "Into this circle I cast my doubt", at the second "I cast my despair", at the third "I cast my fear" and at the fourth "I cast my worry". The more effort and feeling you put into it the better.
Wrap the bramble in the cloth and then close the circle.
Take the bundle and burn it on a fire until it is all ashes.
You can vary the wording depending on what you are trying to dispel and whether you are performing it for yourself or for someone else. You could also try spitting into the circle of bramble. Not very pleasant but it shows even more dislike of the negativity you're trying to banish.