I fantasize about being raped and abused by my gigantic sister.

Ok, first of all, I don't actually HAVE a sister per se, gigantic or otherwise, but for the longest time I've fantasized about having an older, physically massive sister. And I mean massive I mean like 2,10 meters tall, and weighing well over 110 kilos, a bbw, if you will. A woman that could tear me apart with her bear hands if she wanted too, and then having her abusing and force me to do degrading sexual things, such as forcing me to give her cunnilingus after she urinates and lick her clean, washing her in the bath, forcing me to grovel at her feet etc.

But at the same time, she's also protective and possessive of me, like if someone was messing with me, she would go up and break their heads with her bare hands and I were to try and approach another she would beat her up and tell me I better stop seeing her or she'd do the same to me. Stuff like that.

Most of my fantasies revolve around giving her cunnilingus and analingus, while she is sitting on my face, but sometimes I also feel like sucking on her breasts, and fondling her huge fat belly. She always called me 'brother' or 'little brother' too whenever I fantasize about her, that is when she's not calling me names or belittling me.

I know incest fantasies are relatively normal, but this somehow seems to intense and too deliberate (I literally made up a sister just so I could fantasize about her). Is it normal?