Being touched out

How do I deal with being touched out? I’m going insane. I currently have a 6m old and soon to be 4 year old. I’m a sahm with them 24/7 I don’t go out what’so ever. Not even on the weekends bc my husband is too tired from work and I can’t leave the kids bc they constantly want me and cry for me. Like I’m dealing the whole time with my smallest as soon as she’s asleep I want to sit down rest clean catch my breath but then my 4year old constantly needs me and I’m loosing my mind. I want peace and not having to get up every 2 mins. No I don’t have there grandmas or anyone else to watch them. Everyone else works. I just want to sit down and not hear anything noise. I’m tired. What do I do !!