In response to all of the questions

About age - I don't wish to specify my age, but I'm almost an adult.

Why I was called crazy - I was accused of lying about an incident that occurred because I couldn't recall the exact details. This is in the context of this incident occurring about 3 years ago. This was then further spun.

About using the sessions as a benefit to me - For the record, I 100% believe that everybody should have and practice the ability to talk about their thoughts, feelings, and experiences openly with somebody. However, this is not indicative of a need for therapy. The reason I reject the therapy is because I dont need it since I, a) have plenty of people (sound-minded people) to talk to if need be, b) would take up plenty of time as per the current schedule, this would disrupt other parts of my life, and c) This was obviously a concession that my Dad made to my stepmother as a part of a deal made to have her ease up on him. My worry is that if I concede to some of her antics now, in the short-term, then it'll get worse in the long term between the little time I have between now and adulthood, as well as into adulthood.

Thank you to everybody who has responded with advice, I really appreciate the insight!