！
My doubts have all melted away!
Literal
Doubt [subject-が] ice-melted-[polite-past-ました]!
氷解する ('to melt like ice, to dissolve') is a set metaphor for doubts, misunderstandings, or questions resolving completely. Literally 氷 ('ice') + 解 ('melt, resolve') — a crisp compound. Used in the specific sense of an 'aha!' moment when everything becomes clear.