Hi there, I consider myself a witch and I want to say upfront that Sabrina is not very accurate about witchcraft! To me, identifying as a witch is mostly about owning my personal power with responsibility, having meaningful ritual and reflection in my life, and connecting to nature. When I cast a spell for protection, it's more about setting an intention that helps me hold my boundaries than it is about expecting that a supernatural force will actually protect me. I think (tell me if I'm wrong!) that many Christians might say that part of what makes praying a powerful or meaningful experience is the act of praying, not whether or not God answers your prayer. It is similar for me and practicing ritual or celebrating pagan holidays. I do not believe in the devil; I also do not believe in a god or goddess, though some witches do. To me, gods and goddesses are archetypes or symbols for the humbling power of the natural world/the cosmos/different important aspects of life (like death or rebirth). So if I pray to a goddess (say Brigid on Imbolc) it is less believing that goddess actually exists and more honoring what the idea of hey represents in myself and in the world. I think you can find meaning in any kind of prayer or ritual, but you cannot expect miracle cures from any religious tradition, including witchcraft. I use tarot cards to get guidance on things happening in my life, and I do find it helpful and meaningful, but I think it is partially because the cards offer a helpful tool for guided reflection (or, they help me think something through to come to what I already know). I also practice herbal medicine, but honestly that is more grounded in science than magic, and not something anyone should mess around with if they have a serious medical condition and no training, although you could probably find a certified herbalist in your area.
I hope those answers help! It sounds like you are going through a rough time. I hope that things get better for you.