The phrase "loses control oneself" can be replaced with a variety of synonyms, each of which might be more appropriate depending on the context. For example, "freaks out" and "melts down" both suggest a loss of control stemming from stress or extreme emotional reactions, while "errs" or "strays" might be more useful in describing someone who has made a mistake or taken the wrong path. Other synonyms for "loses control oneself" might include "blows up," "loses it," "cracks," "snaps," or "goes off the rails." Ultimately, the choice of synonym will depend on the message the writer or speaker is trying to convey and the tone they wish to use.