I feel resentful and bitter about the fact my child is autistic

Please don’t bash me. I guess I am just mourning the life I thought I’d have with my eldest son. He was officially diagnosed with both ADHD, autism with SPD yesterday and I’m just really depressed. He’s only 4 but I’ve never been able to really enjoy parenting with him. He has screamed and cried about everything basically since birth. Going anywhere with him is an absolute nightmare and now that he’s in school his teachers just tell me something negative every day like that he doesn’t comply with anything they ask him and he’s not doing any of his work. I can’t even really talk to him because when I try to he just starts talking about something unrelated like the an air vent in the ceiling or a bug he saw five days ago. Truly I just don’t feel like I’m cut out to be a special needs parent. I have no patience with him and when he melts down I don’t know what to do and I just have to walk away to avoid telling him to just shut the fuck up. I’m sorry I know that sounds harsh but I’m seriously seriously struggling with this and don’t know what to do about it.