Am i setting myself up for a breakdown by taking AP us history and AP biology in the same year?

How much homework is there for each, and how are the tests? I dont know whether i should change from AP biology back to chemistry or stay with the 2 APs. If i take chemistry this year, i will have to take AP bio junior year, and i dont know how that will work out with other AP classes. Any personal experiences will help, as well as what colleges say about each class. Thanks so much! You guys are amazing :)