How do I get more fps streaming?

Yesterday I streamed a little bit of CS GO on Twitch with streamlabs OBS and as long as I just played, everything went fine. But when I also opened Discord and talked to others, nothing worked. My fps are dropped to 20. Can someone help me which attitude are good for streamlabs OBS to prevent that?

Tell me first what your PC has installed so.

CPU
GPU
R.A.M.

how fast is your internet?

Which parts are installed in the PC? And take screenshots of your settings and post the link below this post.

Well I'm not at home right now, but I know that I have 16GB of RAM and the Internet will not be a problem anyway, because I have fiber with Max. Down / Upload 1 Gbit / s

But my hardware probably will not be, because they're all expensive gaming components.

Without information that is bad to say. Helpful is, inter alia, a Ryzen 6 core CPU. Sufficient RAM and of course a reasonable GPU.

Can I do this tonight, I'm working.

Yes, then your settings are wrong.

But I do not know what's wrong with that.

I can tell you if you can tell me what you've set everything. Because my system is 6 years old and I only have a 100k line. Streame but Lagfrei in 1080p 60fps no matter what I do by the way.