Wow! Moving house - yes, I think that qualifies as one of those major events that stresses out most people I know! Socially anxious or not, moving is stressful.
Give yourself credit. You are carrying on with Session 3. You are CARRYING ON! Marvelous. Setbacks are a sign of progress. I always remind myself of that, because it's exactly at those moments of despair and feelings of a setback or that we've made no progress - it's then that we want to just throw our hands up and quit. That is the feeling we go to. But - setbacks are a sign of progress. You're feeling that competing neural pathway, the new one that is going to get stronger and healthier, but you're still feeling the older and currently stronger way of thinking, that neural pathway, that keeps us with ANTs for now.
You're in session 3. Still so soon along the path of cognitive therapy. Don't be too hard on yourself. Addressing ANTs is the way to go, just as you are doing. Conquering, obliterating, making ANTs completely disappear right now - that's not the right approach and not even physically possible for us, so don't put yourself up against the impossible and feel like you're failing. You're doing the right thing by continuing to address your irrational ANTs now, and then again, as much as you can without resisting in the next 10 minutes when they come back, and then in the next hour when they might, and then later when they might. And all those times you reinforce that new option of dealing with ANTs the right way, they stop coming around as often.
For me I used to feel I had these spikes of inexplicable depression. Later, and this is what finally led me to realize it was social anxiety I was dealing with, I realized those feelings were sparked by something earlier, something I didn't even consider, sparked by that autopilot ANT in my head or by something more "in my face" and obvious.
I like to read in your post that you acknowledge you are having an incredibly stressful month. The move, etc. - yes, that's rational. It's a stressful month for you. Yes, you feel alone, but you have reminded yourself rationally that you are not alone in such feelings. And you're carrying on. Persistence, practice, patience.