Puppy blues exhausted

I have a 6,5 month old golden retriever. Inside the house he is calm and listens pretty well but the moment we step outside he is incredibly exhausting and a completely different dog.

He pulls A LOT and only listens to my commands when he feels like it and when there are no distractions around. He eats EVERYTHING on the ground, always. When we go over to a friends house he is not able to calm down for hours. He’s very jumpy and whiny when I leave the room. I’ve been consistent with my training since day 1 but it seems like I just have a puppy with a strong mind of his own (and spend a lot of time informing myself on what’s the right training on all topics mentioned above).

On top of that he has epilepsy which adds to my stress levels. There hasn’t been a month where he wasn’t so hyper the moment we are not alone, which makes me scared that the behaviour is there to stay.

Any people who’ve seen bad behaviour consistent throughout puppyhood?