I've cancelled my subscription yesterday, conveniently it was about to renew at the end of the week, so I have a few days to migrate from Proton, here's what I'm thinking of, but I'd love to hear what other people are switching to
Been using AirVPN. Just make sure you use the wireguard config, not the tcp openvpn (not sure about the udp openvpn, but people seem to recommend the wireguard option and I accidentally used the tcp openvpn config at first).
Seconding KeypassXC.