The upcoming exam looms large in my mind.
loom large
idiomTo have a great deal of importance, presence, power, or sway; to be of great significance or concern, especially when posing a likely threat or danger.
With the deadline only two days away, the unfinished project looms large over the entire team.
The threat of economic instability looms large, casting a shadow over the government's ambitious plans for long-term growth and social reform.