Weigh upon" is a common phrase used to describe how something is mentally or emotionally burdensome. There are several synonyms for this phrase that can be used instead to convey the same meaning. One possible synonym is "bother," which means to cause trouble or difficulty for someone. Another alternative is "oppress," which denotes the feeling of being weighed down or confined by something or someone else. Other options include "tax," "burden," and "beset," all of which express a similar notion of pressure or strain. Regardless of the synonym chosen, it is clear that this phrase represents a sense of heaviness that can have a significant impact on one's life.