Hi Danda,
Before abandoning SecureLine, I would recommend trying to connect to different servers if the speed reduction is that severe. By default, the app will connect to the "Optimal" server, which is simply the nearest server geographically - if you are using the VPN whilst connected to a streaming service, I would recommend using one of the streaming locations (as these are better optimized for streaming video rather than typical internet browsing, and can provide a better connection whilst streaming).