The phrase "come a cropper" means to fail or experience a mishap. If you'd like to add some variety to your expressions, you may consider one of the many synonymous idioms. For instance, you could use the phrase "fall on hard times" to suggest financial or personal difficulty. Another way of expressing the same idea is to say "hit rock bottom" implying a period of intense struggle. Other related idioms include "bite the dust," "crash and burn," or "come up short." However, it's worth noting that each has slightly different connotations or nuances, so it's essential to use them appropriately in context.