Yep sounds like inappropriate play. Definitely try the Bitter Apple spray on your arms. And I *would put him in his crate for five minutes or so when he gets wound up like that. Give him a stuffed bone, or kong, anything that entertains him. It is more like a time out, than a punishment. It helps the dog calm down.
Another thing that helps is find a way to interact with him in a constructive way (like clicker training) and then engage him in that BEFORE he starts to nip. He nips because he wants your attention. If you give him your attention while playing by YOUR rules, you will both win
I would definitely sign him up for some classes ASAP…try to find one that uses treat training, as I doubt you would be able to engage this type of dog with any other type of training. You will both enjoy it, and I think it will help him focus.