To those with step-parents, is this normal?

in 2019, my mum got married to this guy. I'll call him J as that is what his forst name starts with. At the beginning, J was nice, chilled, bought me and my brother stuff, nice things like that. me and my brother were really happy to have someone like him. My brothers dad left when he was two months old and mine when i was six years old (my brother is older). Then, my mum and J got married around two years later; i know because i was either sven or eight. The bad stuff started happening after that. we went to france, he was telling me and my brother to stop eating so many sweet things because we will gain more weight. The thing about that is, we werent eating much sweet things, ony small treats here and there like any normal child. He slowly got more spiteful as the monthswent by, my brother is qalmost fourteen and already is living with our nan insead of at the house because he couldnt take it anymore and lashed out. Step-dad has made me cry/ burst into tears for no reason, just being rude without telling why, swearing at me for things havent done, obviously favoring younger brother,whos name also begins with J. He began convincing our mum to reducing nice things from us, spending less money on us, being less supportive of our descisions, things like that. He makes fun of my friends in my face, tells me when my friends ditch me for no reason that its my fault and should have seen it happening. I already have severe truse issues and slight anxiety, my older brother has autism and possibly ADHD. I have shown some signs of dyslexia throughout the last few months but if i told him, he wouldnt allow me to get that checked. This isnt even all of it, just some things. For the record, i have just started year seven and my life is already hell. I have thought about 'leaving earth' a few times or leaving my house but i thinks he can tell and he moniters my phone so i cant ask friends for help unless its in school, but we have different friend groups. He is controlling my life and my mum is too oblivious.Is this the case, or something similar for you?