My boyfriend is fucking huge and I'm relatively new to this. Help.

I've tried warming myself up with plugs, but the plugs I have still seem way too small in comparison to him. I want to feel him in me so bad but right now trying anything hurts and goes nowhere. I wind up just having to use toys on him to make him cum and I feel so useless. Does anyone know any good brands of trainer plugs I could maybe get to warm up to him? Or some technique to relax i just don't know about? Something. Anything.