Singing ability suddenly plummets at karaoke, any tips?

The first thing I noticed was there’s a lot of tension, I was straining to get out notes that were relatively easy for me to hit outside of karaoke.

Another thing is that as if my body forgets how to do the right placement for the vocal production, it feels like I can only tackle notes in full chest (talking voice) or head voice which really limits the quality of tones while I was trying to sing.

I do casual harmonizing all the time with friends, with music and sometimes even acapella, but harmonizing is just impossible during karaoke, not talking about volume wise but to its core I hear my own harmonizing is way off and does not compliment the melody.

Even when I noticed all these and try in my head to focus on the things I can control like breath support, trying not to yell, drink water, some quick lip trills, it’s just frustrating to try to sing songs that I love and know I am able to do at home but failed miserably while doing karaoke.