What is your opinion on challenging thoughts?

So I’ve been practicing living presently for a while now. I’m working a very peaceful job which allows me to observe my mind for extended periods of the day.

But I have to be honest, after doing this for a while, it gives me the most ugly, disgusting, cringe inducing thoughts… some of which actually happened. I continue to observe but it continues to be mean.

I started challenging my thoughts last night because I was pretty fed up, “no that’s not true.” “Yeah I did that. So what?” Etc.

What’s your opinion on this practice? It seems that challenging/engaging is contrary to ET’s teachings but it does make me feel better.