Please help

I am at my wits end with my 18 month old. He used to sleep from 7-7 every night, no night time wakings, and typically he’d wake up happy as a clam. Well, now he wakes up for the day anywhere from 4:30-6 am every single day with 1-2 night time wakings. I feel like he’s a newborn again, and I am beyond sleep deprived. I haven’t had a full night of rest in 4 months because of this. I have tried damn near everything, and I am unsure of what I’m supposed to do now. I’m so angry with him that I just sit in the living room sobbing sometimes while he cries in his room. That’s what I’m currently doing at the moment, actually. I’m scared for my sanity and for my mental health at this point. 💔