If you want full anonymity performance be damned you can run your VPN over Tor. But I gotta ask, what is the problem with your ISP recognizing that you're using a VPN? Everyone is using VPNs nowadays.

If your concern is that they'd know who you are connecting to, you can use another VPN you trust more than your ISP as a middle-man.

If you trust no-one but your friend, I'd recommend running your own fiber to your friend's house, but people could just see where it leads to, so what you're looking after that is to invent quantum-entangled network cards and pick up your Turing award and possibly Nobel on your way out. If that seems out of reach, I can't see how to solve this with technology.