Keep your levels incoming via UR22 at safe levels.
In the audio mixer insert first a compressor, then a limiter. Stick the limiter to -2dB (the brickwall for even the loudest parts in whatever you send).
Then head over to the compressor, start with a ratio of 1.5:1 , start with a gain-up of +2 or +4 dB and play with the treshold. The lower you set the threshold, the "earlier" the compressor steps in.
If still to low in average replay level, step up with the ratio to 2:1, try to avoid more. If your incoming level far too low, gain up on the UR22 carefully (the red peak LEDs should remain off for almost anytime. That should work, if not, increase the gain-up to +6 or so. If more needed something with your incoming levels is seriously an issue.
The general rule-of-thumb is that the "un-hearable" compressor is the best one. If your sound sounds squeezed and pumping (only to reach for a loud level), it's totally ruined.
2nd rule-of-thumb: If the signal steady peaks to the -2 dB mark within the audio mixer, then its permanently hold by the last-man-standing limiter (you are steadily poking against the limiter). Thats not good. If you reach the wished average level in the stream/recording, peaks mostly kept narrow below -2dB and it sounds still not squeezed, then its perfect!
You can proof your "average level" reached (correctly named loudness) by installing and inserting "dpMeter5" (its free available) as the last one in the filter chain (even behind the limiter). If you reach for -14 (for Youtube, i think facebook should be nearby) over a couple of minutes then you _know_ that your outgoing levels are right. =)
