The time of the year is lack of daylight. Seasonal affective disorder.
SAD.
Mood swings (depression) is nothing new for the dark days of winter.
There is light therapy, drug therapy (legal and otherwise) getting out and active will help.
Sorry to hear about the tought times...sharing with sympathetic souls will help.
Admitting you need help dealing will likely get you better results than thinking that you are weak if you seek help.
Good luck to all.
Don't be afraid to reach out.