@EmeraldShamrock
Please do, ultimately we don't hold babies/toddlers accountable for misbehaving, teenagers aren't the same of course, but toddlers/babies misbehave/scream because they are frustrated or have needs but don't know how to properly express them, it's the same with teenagers.
I had so much anger/pain as a teenager, I didn't always express it in the appropriate way but teenagers go through all those hormones and aren't fully wired yet to channel their emotion/feelings in a productive let alone mature way. I definitely wasn't but then again, nobody is always ever ready to face and deal properly with some things life throw at them.
I think I would have benefited from therapy (and learning to talk about my problems, express them in a different way than anger/ lashing out) as an early teen, I had therapy eventually but I did it in those years and not much later.
I think most of us have pushed boundaries at some point in our lives and I think we all benefited from not being reduced to the mistake we have made like some sort of permanent tattoo.
I don't think people who get frustrated/angry at their child's attitude and behavior are failing but I definitely feel like parents who give up on their kids when it gets hard are failing them. I definitely feel like parents who have decided that their 4, 9 or else yo kid is naturally ''unlikeable'' are massively failing them and setting them up for a life of low self-esteem, no matter how well they think they are hiding it (you can't fully hide those things) same with parents who seem to only cope with kids who are ''easy'' and yet seem to have convinced themselves it's totally normal.
I think if my mother had been less focused on the behavior and how much she disliked me/it and how much she had sacrificed to raise me for me ''turn out that way'' she would have maybe tried and digged the reason why I was misbehaving and feeling that way, and maybe she would have understood that it wasn't about her (well not fully anyway). OP, you are a single mother and no doubt it's been hard, and no doubt this situation is likely awful for you, but maybe your son is misbehaving/acting out because of the fact that he didn't have a father/other deep things that may have looked liked he was dealing fine with in his earlier years but is finally coming out now that he is older and having a hard time dealing with.
Separate from my sexual abuse, a lot of my childhood trauma/not having a father, came out during my teenage years. Until then anybody would have thought I had been fine with it because it had (almost) always been the status quo. Teenage years bring out the worst in you, including deeply buried things you never imagined would come up. So I would look into family therapy, so maybe you can learn to connect again or at least speak to each other in a neutral space.