First, please forgive the long email. I guess I had a lot to say about this.
In the way I practice my faith there is no seperation between Cerridwyn and Hecate, or any other face of the Goddess. There is only one Goddess who is multifaceted just like any human personality is. In reality (at least the way I see it) there is only one Goddess, not hundreds of individual entities which make up Goddess, though I do not think it is wrong to think of Her that way. She appears in any form She chooses and takes on attributes to suit a purpose.
I think the real question to ask right now is why has the dark aspect of the Goddess has called to you. Both Hecate and Cerridwyn are Crone Goddesses. In my tradition the Crone's main symbolism is as a keeper of wisdom and as She who tends the flames of transformation. In her darker, less understood face She causes fear as She bids you to look into the shadows of yourself and find those things within you that you may not like to see. She does this to help bring about balance within you and so you can love yourself completely. She is the gateway to the unknown, the mystery which we are afraid to uncover within ourselves. Her element is fire and I often find it helpful to use a candle flame or the fire in my wood burning stove to connect with Her when the moon wanes. Open up your third eye chakra and let yourself be open to connection.
A Crone meditation could involve going through a cave to then come through it into an open space where She is there tending Her large cauldron over a fire. Speak with Her and listen closely to what She has to tell you. She may bid you to gaze into Her cauldron. Your reflection will be Her own for Her wisdom is always present within you. What else do you see in the murky liguid? Impart with Her any gifts that you may have, embrace Her, and turn back - coming out of the cave feeling refreshed and aware of who you are.
I hope these things are helpful to you. In my tradition there is nothing to fear of the Crone once She is understood and connected with. I consider fear to be the dark aspect of the Crone Goddess.
So, I don't think you have a choice to make. The Crone has made it Her time to connect with you, to impart Her wisdom upon you at this time. I see this as a period of transformation for you. I would not be surprised to hear that the Maiden makes Herself known next, guiding you towards knowing yourself and embracing Her freedom. The Maiden will give you new insight and then the Mother may come to you, teaching you how to grow and nourish your spirit so that you may be able to love all others in true compassion. After this the Crone may again make Her presence felt and the cycle will continue all over again. I believe this to be a way towards enlightenment.
I understand your confusion. It is frustrating to be journeying alone, but that is the way it must be for all of us.
Remember this is my path and I don't claim to know that it is truth nor do I believe it is the only way of the Goddess. No one can really know the truth of such things. We can only believe. I believe the Goddess has called to you in Her Crone aspect because now is a time for you to come into your own and embrace your path completely. She will guide you through the shadows and the depths of your mind to a place of understanding. Many blessings on your journey.