My parents depend on the 50,000 yen I send them every month.
Literal
Parents [topic-は] my monthly 50,000-yen [possessive-の] remittance [object-を] are-counting-on.
仕送り is a specific word for money sent home — typically from a working child to aging parents, or from parents to a student living away. あてにする (to count on/depend on) + ている shows ongoing reliance. 月々 (monthly) uses the 々 repeat marker. 僕 marks the speaker as male.