Puppy biting need help

So we’ve had our border terrier now for just over a week, he’s coming up to 10 weeks now and the puppy biting is getting out of control. My partner and I can’t even sit on the sofa without him launching at us and biting at anything that’s there, sleeves, pant legs, skin. We have tried redirecting, he goes back to biting us. We have tried correcting, it’s just makes him worse. We’ve tried the yelp, he doesn’t care. We have tried walking away, he just latches on and attacks our ankles, pants, socks. When he gets really bad we’ve resorted to time outs in his crate, but I’m wary that doing this is using the crate for punishment and he’s just going to end up constantly in his crate as it’s all the time he’s doing it unless I’m actively doing training with him. I’m at a bit of a loss as he is drawing blood on both of us. Otherwise he’s an angel, doesn’t cry at night in his crate, has already learnt sit and come, working on stay and down. But this biting is insane. I’m exhausted to be honest, I’ve never had a puppy before only older rescue dogs so I’ve never had to do this before. People are telling me it’s normal but I am starting to worry. Do we just need to keep at it or is there something else we can try.