'De lo contrario' means 'Si no es así': On the contrary. Example: Me voy a casar con Mateo, de lo contrario, me quedaré sola. If I'm not going to marry Mateo, I'll stay solitary for the rest of my life. 'Lo dicho' can mean 'Lo mismo': Example: Lo dicho, no te dejaré ir hasta que cumplas los 18 años. 'As I said before...' When you're talking with someone, and you want to finish the conversation, and you say, for example: "Lo dicho, te veo mañana", because you previously said "see you tomorrow" but you went on with the conversation.