I'm not a streamer so can't really give you good advice. What I can say is it's okay to be human. You don't have to be all smiles and positivity all the time. My advice, but it's more for in general and may not work for you, is to try and give yourself a couple of hours peace before. There have been days I've had to be among people, but I felt I couldn't, so I'd go to a cafe, take a walk by the river under the trees, and spent time alone, quiet, and chilling. That helps me to then be all smiles