How do I stop translating 'I want' in my head before speaking?

I've been studying for six months, but whenever I try to jump into a conversation, I freeze up trying to attach the right case suffixes in Malayalam. I know the basic rules, but I can't generate sentences in real-time. I'm thinking of using Chickytutor.com to practice spontaneous speaking because I need to build muscle memory for these suffixes without stopping to think about the grammar rules every time.