Dealing with Sensory Overload and Alexithymia

Lately I’ve been dissociating a lot. I’m not sure if it’s ptsd or anxiety related, or even from something else. But it’s getting bad. I dissociated for like whole day a few days ago. I thought leaving the house would help but I ended up buying things I didn’t need and embarrassing myself at the store in front of strangers. There’s been a new thing going on at home that’s triggering me, but I feel like I’m not myself anymore bc I’m so stressed all the time. I’m not too familiar with dissociating, but I’m almost positive that’s what’s going on. I’ll know things are real, but they don’t feel real. Sometimes it feels like this world is real but I’m only half here. Other times it feels like nothing is real and I feel like I’m dreaming and when I wake up everything will be normal. I know I’ll regret things later, but it feels like it doesn’t matter what I do. I’m scared I’m going to do something I’ll regret. Does any one have any tips for in the moment? I can’t figure out to pull myself out of it and be able to function. I can’t get rid of the trigger, so I have to find ways to cope with it. I can’t handle feeling so off all the time

I'm currently going through an ASD Diagnostics process and it's brought to my attention that I may also have Alexithymia which would explain why it's so hard to figure out which alter, or alters are present. It feels like since I have a hard time differentiating between alters I may always have this problem. Also recently I got an app called Antar that helps me communicate with them and it's been better than other "self" communicating apps for me. But does anyone else have this problem because they can't just "know" what they're feeling or why they're thinking thoughts?

Im not sure if i really do dissociate but sometimes i could be doing anything and i would just; realize im alive and i can control something without thinking and that everything is real and not fake