Texted my ex again and now I can’t even sleep?

My ex betrayed me. I thought if I just text them that could work. I noticed I wasn’t sleeping at all at night. After two nights of no sleep. I told them I needed space again to heal and get better. Now last night I got no sleep again. Literally..0 hours. I’m just looking for some reassurance because I thought texting them would be fine, but they started saying some guilt tripping things to me again..and I feel like now my body is hypervigilant.