Thank you for giving us the opportunity to respond to your question. I am glad you are taking the time to write about it now, before the holiday season gets in full swing. I want to respond by (no pun intended) shedding some light on SAD -Seasonal Affective Disorder.
There are three things that jump out at me. The first is that you say this happens the same time every year. This time of year is notorious for Seasonal Affective Disorder due to the radical shift in the available light. The clocks fall back, the sun is less available and this causes real changes in our biochemistry, particularly with melatonin and vitamin D, both of which are drastically affected by sunlight. I would consult a knowlagable healthcare professional about such things as supplements and light therapy (the use of artificial light in the treatment of SAD.)
This possibility is further highlighted by the fact you are home-schooled and your primary exercise is dance—an indoor activity. While estimates vary, 20 minutes of exposure to sunlight daily will usually be of tremendous help. The problem is being outside for 20 minutes doesn’t happen regularly in the colder months, and when it does we are covered head to toe, so the sunlight may not reach us. In the summer months we often get what we need without thinking about it.
Finally, I would note that being home-schooled often reduces the number of social interactions a person has. This typically has a correlation with feeling a bit more isolated. I would encourage you to get involved with other social groups if this is your situation. More friends and connections tends to help us when we feel this way.
If these suggestions don’t bring about some relief within the next 60 days I would encourage you to find a therapist to explore other possibilities. The find help tab at the top of the page will direct you to someone in your area.
Wishing you patience and peace,