Age related behaviour or not? Hitting and difficult behaviour

My partner had a lot of issues growing up with his behaviour from a young boy and still does in his 40’s. Hes in the process of waiting to be assessed as it’s always impacted his life. Our 3 year old son has become such a handful I’m not sure if it’s typical for his age or if he needs further assessment/support? He acts the same way my mil would describe my partner as a boy. I’ve always felt our son has shown traits that seem autistic or sensory/neurodivergent. I’d appreciate thoughts on his behaviour below, thank you. Lately he’s been lashing out a lot. He has tantrums but will be violent and hurt us. We’ve tried so many things and he still does it. Sometimes we play fight and that’s ok but he is really vicious such as trying to push our eyes from a young age, head butting, grabbing and kicking my partners stoma bag, scratching, biting, punching and kicking. He gets so angry and lashes out, will feel bad once we speak to him about it but will do it again shortly after. He keeps saying he doesn’t love us anymore when it suits him, this is since his baby brother come home. Hes always hated loud noises and covers his ears. He gets so angry if something he is doing is changed or someone does something he doesn’t want in play etc. Hes very clever but it’s really difficult to get through to him, he will ignore and not listen/respond like he’s in his own world. He doesn’t vocalise how he feels or his wants since he was young. He points and makes a noise and I have to guess what he’s saying. He has no sense of danger really. He gets easily overwhelmed. Hes a very fussy eater and eats the same bland plain food everyday and will hardly ever try anything new. He is sensitive to bright light. There’s probably more I’ve not thought of but this is the bulk of it. It’s got to the point where I am really struggling with him every day and I now dread how he’s going to be at any moment which I’m gutted about. I feel I’m a decent parent and he gets a lot of love from us all. I keep blaming myself and feeling guilty but now we’ve spoken about him being similar to my partner, I wonder if it’s something more that needs help. Would appreciate your thoughts.