Black Tourmaline Tumbled
This stone will help you in so many ways. The negative ions of black tourmaline will encourage clear thinking and lightheartedness.
It will also protect you from negative energies by absorbing negative energies and psychic attacks directed at you, and then sending them back to whoever gave them to you. Which makes it a very powerful karma stone, too.
It will create an energetic boundary between you and other people so that you don't pick up their negative energies.
Black tourmaline is also a great stone to have because it can ground your body. It's very strongly connected to the root chakra, but it can help you balance and open all your chakras.