If someone I liked for 10 years said that to me, I'd be very excited!
Having that said to me after ten years of liking him would be crazy!
If someone I liked for 10 years「もし十年も好きだった人に」 said that to me「好きだと言われたら」, I'd be very excited!「とても興奮するだろうな」
Having that said to me「そういわれたら」 after ten years of liking him「十年もあの人が好きだったら」 would be crazy!「ヤバいんじゃない!」