This spell is best done on Friday (matters of the heart) or Saturday (banishing pain). If you need it regards of a different issue, choose an appropriate day of the week here.
You will need a rosemary essential oil or incense, one black and one white candle, black pen, parchment paper and a heatproof dish.
Sit in a quiet place, calm you mind while you burn the rosemary oil or incense. You may invite a healing deity, depending on what you want to mend. Check out the antient goddess here. You can say for example following: "Great Goddess (name), please join me as I purge my heart of pain. Please release me from this hurt and mend my heart".
Light the black candle while you focus on you pain, write all what consumes you (pain and broken feelings) on the piece of paper. Light it with the candle flame and let it burn away in a heatproof dish and say "As this paper burns, so burns my pain and sorrow. I release them to the Universe and free myself from suffering". Light the white candle, imagine you are filled with a healing white light send to you from above. When it feels right, release and thank the goddess and let both candles to burn down.