Honeslty you dont need to use a VPN with nostr, at all. I dont know who told you that but they are doubling your latency issues. You should be fine using your ordinary IP. Make sure that you prune your relays, add a few paid relays, like I stated previously, and also be prepared to wait a little bit for things to sync up. Until you get your nostr client streamlined and setup efficiently, you're going to have to deal with a lot of lag, things that dont seem to be working fast, etc.