teenage biting (aka the biting from puppyhood only got worse)

I’m really struggling. I’m not sure if i’m coming here for advice or support but i’m really struggling. I love my baby. He’s an 11 month old golden and I’d never trade him for the world. He has not stopped struggling with biting since I brought him home. I’ve done every tip, advice, enrichment, schedule change, trainer, etc that you could name, and he’s not stopping. I’ve had him checked by docs to see if there are medical issues underlying… nothing. I think what he is doing is arousal biting because it seems like once he starts, he can’t stop and it’s like a switch that flips. Often times when he doesn’t get what he wants too. It seems like maybe he’s just trying to play really rough, and i’ve had trainers tell me it’s not aggression it’s just inappropriate boundaries he’s crossing. He’s 81lbs already but he jumps and bites like a puppy.

Im torn up. Physically and mentally. I’ve got scars everywhere, my arms are so discolored it’s not even funny, and i’ve gotten to the point where I can’t trust his next move and i’m filled with anxiety. Yet to him, it seems like either a game or he’s taking his frustrations out on me just to turn around and want to play and give kisses. Sometimes I get stuck outside with him in his attack mode and i’m stuck outside for hours… i’m not kidding.. just fighting his biting and trying to get to a tree or pole to tie his leash to. I don’t know how to teach him, help him understand, or help myself at this point and i’m really stressed.

I guess I don’t know what i’m looking for but maybe just to know someone else has been here would be nice. I feel crazy. I feel crazy for hating this stage and I feel like my love for dogs has changed because this is so hard. I can’t handle any negative comments, so please refrain from commenting if that’s the goal. I just need kindness & gentleness because i’m really hurting and I want to love him 100% but this is the hardest thing i’ve ever done in my life. I made a commitment to him and I will forever stand by it even if it means I’m miserable, but it’s true, I am so miserable. And I hate myself for saying it.