Clingy baby/toddler

I need help. At this point I am absolutely desperate. My daughter is 12 months old and she refuses to let me put her down for anything. She constantly has to be directly on top of me! I can’t even go to the bathroom without her! Every time I try to step away for a moment or if i even stand up without her she screams like I’ve just hit her or something. If I leave the room at all she will try and follow me and just wail and wail. I’m going to go crazy. I’m overwhelmed and touched out. Has anyone else dealt with this level of cling with your toddlers? How did you handle it?