Why do siblings do really bad things and then lie about it then call you the lier?

when i was a kid my brother and sister used to beat me and my mom up all the time and my life was allways hell and now my husband and i was tring to get on home makeover so i put my life story on there website and my sister and brother started calling me a lier and the hole thing is thay both are 10 to 12 years older then me and i was just a kid i have no reson to lie why are thay doing this to me