If I'm understanding ERP correctly, it's not doing ANYTHING that would help soothe you, right? In my case I'll have a thought > usually I'll have my husband check things for me, if no-one is around to check things for me, I'll say to myself (in my head or out-loud) "I would never do xyz" "I didn't even get up from where I was, if I did I would've remembered walking to and from" (just examples). These are all compulsions, right? So I can't even mentally soothe myself. If I'm going to do ERP correctly, how do y'all stop the mental compulsions?

A compulsion is any behavior that is intended to stop the anxiety, or to convince yourself the thoughts aren’t real. So if you find yourself researching, checking, generally trying to give yourself “proof” that you’re not a bad person, etc… that would all be compulsions that you want to avoid. Most of my compulsions are mental - repetitive prayers, trying to reason things out in my head, rumination, etc. They can be hard to avoid because you can’t exactly turn off your thoughts. The thing that helps me is to basically just tell myself that it is OK to feel anxious and panicked right now, that I don’t need to solve it right now, and then to just do my best to get involved in something else - be that work, a video game, watching YouTube videos (unrelated to what I’m worried about obviously,) etc. Or even just mindfulness meditation, focusing on just regular physical sensations like how breathing feels or the weight of my body contacting the chair I’m sitting on, helps.

I've watched a video where it says not to do any relaxation techniques, like deep breathing, because it can make ERP less effective. What do y'all think about that? I just want to make sure that I'm going to do this right.

Also, they say to sit with the anxiety... I like the idea of shifting my attention to something else, I feel like that would be less uncomfortable. There's just so much information out there.

It can be super hard to stop mental compulsions, especially at first! It gets easier with practice. One thing that helps me is the option to “spoil” a compulsion after the fact. For example, if you tell yourself “I would never do xyz,” you can spoil it afterwards by saying “actually, I might do xyz.” Ask your therapist about this technique to see how it might apply for you. Also, remember to take time to relax and rest outside of exposure time! Starting ERP is exhausting, so you might need more sleep than usual.