Need advice on Harley's behavior

Hello everyone, Harley is 9 Months old and I'm finding it really hard to deal with his behavior   I was just after some advice on how you lot dealt with the terrible teenage phase. It all came to a head yesterday when we were in class doing a little bit of agility and it was Harley turn to have a go at the little jumps and tunnel and he bit me on the leg and would not let go for love no money and as a result he has punctured and bruised my leg. He will not come in from the garden only for bones or big treats if i go out there because he has a tendency to chew he will jump up and bite and will not let go. I feel really upset and don't know what to do because it really hurts and hes like hes forgotten all his commands and reverted back to when he was a puppy jumping up all the time. The only time he will let go of me is if i take a can out with coins in and give it a little shake.
He is also nipping more on walks if he doesn't go where he wants he will nip the lead and my legs. Any advice would be great. Thanks

Back to basics I'm afraid. Turn your back and ignore to help with the jumping. The shaking can will help with the nipping. He is testing his boundaries which can indeed be very troubling. Also make sure everyone he comes into contact with enforces the rules the same way.

I agree with the above Beth. It's so disappointing when they revert back like this. Make sure that everyone he comes into contact with reacts in the same way you do so that he doesn't get mixed messages.

think a staffy teenager is a bit like an ordinary one all good advice nothing i can't add

I recently went through this with Casper. He'd actually stand outside barking at me by the back door if I wanted him to come in. So I took to standing behind the door and waited for his curiosity to take over, then once he had come to see what was behind the door and what I was doing, I turned my back until he sat next to me. Then he got the treat I and been hiding. It did take a few days for him to go from him jumping at me behind the door, for him to sit by me until I was ready, but thankfully he hasn't gone back to being difficult about coming in since. He is also slowly learning not to jump and nip my arms as I've worked hard at totally ignoring him. One thing I have found has helped, is to not let him on the sofa any more. He wants my attention he stays by my feet calmly. If he jumps on to the sofa I just get up and stand with my back to him until he comes to sit in front of me. This has literally only been something I've tried in the last couple of weeks but so far it's working and making it easier to get him back to the good boy I've been used to.