It means you need a better provider.
Yes, a VPN will slow down your connection. I’ve tried a few, and all have slowed my connection to some extent.
Try changing your DNS server to Google DNS and change your port and location. If buffering persists, change your player. If nothing works, your provider might be overloaded.
Pretty good speed for a VPN. Upload could be a bit higher, but overall it should work well! Probably an issue with your provider.
Ping and download speeds seem fine for TV here. You can expect some speed loss since you’re tunneling through another network, which can introduce various factors affecting speed. I’d recommend talking to your provider about it.
It’s your provider.
Get rid of your lousy provider.
I use IPVanish and get 90% or better of what I pay for. Try different server locations.
The buffering might be due to your Firestick or content provider. Your lower speed should be sufficient for normal streaming. For a decent pre-watch buffer, your Firestick needs storage space; how much do you have free?