My puppy is 22 weeks old now and just housetrained. I was surprised too. I'm a long time dog owner but I always adopted adult dogs, and they were easy to house train. I know it's stressful.
If you can afford it, doggie day care a couple of times a week is a great outlet for energy and helps with socialization. I don't know where you live, but Dog's Day Farm does evaluations of pups and then can match them to similar temperament dogs while they are there playing. I don't know if any other day cares do that, but I'd ask.
Your Dogs Friend is a nonprofit dog training organization in Rockville with many online classes. But they also have in person "puppy parties" based on weight, and that's a very controlled environment where they can let puppies play together under strict supervision. They are such a great resource. They might have some great insight for you.
As far as "not responding well" to training, it might be a time thing. I sit and train my puppy 2-3 times a day in 5-10 minute bursts. I also use treats outside for every good behavior. It's a lot of work, no doubt. And I only have older teens so they are autonomous enough that I actually have time to do this. I realize not everyone does. Just putting it out there in case you aren't....and somehow think you might be able to do this.
Here's Your Dog's Friend's website if you want to browse it.
https://yourdogsfriend.org/