Slutsie
You do indeed need a safe-word. One it will allow him to know that he can't do something that hurts you in any real way, two it will also let you relax more and he will sense that.

You should begin to let your sub out around the house, pamper him, call him a special name letting him know you are his sub and proud of it, next you should try to be sure that he has things he wants before he knows he needs or wants them, in other words treat him like a Dom.

Talk to him, get him books on the Life, Loving Dominant, Screw the Roses give me the Thorns, possible rent or buy the Secretary, so that he get to learn about the life.

My favorite is for you to buy a set of real handcuffs, double locks, dress in sexiest garb you have, cuff your hands behind your back with key in mouth. Then go to him give him the key from your mouth, then ask him nicely to expose his cock and kneel before him while engulfing his cock with your mouth alone. I bet it isn't very long before he becomes your will Dom.