Fireworks are going off in bed, but you aren't getting off. As you already hinted, you are never going to get off as long as you continue pretending. The predicament for you lies in the fact that telling your mate that he's not meeting your needs sexually means admitting to having lied all along.
So what can you do? Two choices.
Option 1: Tell your mate the truth, which will probably set fireworks off in him. To minimize the fallout, you must put all the responsibility on yourself. Tell your mate that you initially lied because you were too shy to tell him what pleases you (or you didn't know what pleased you) or that you were afraid to hurt his feelings. And, explain that before long you were boxed in (or should I say box springed in). Reassure him that you know he's a good lover and that you are sure that, with honest communication, he will be able to please you for real. Be prepared to deal with various emotional reactions on his part (hurt, anger, betrayal. ) Listen and understand.
Option 2: As an alternate to telling your mate that you've been faking it is to simply say that your sexual tastes are changing. Then simply communicate in actions and words what 'new' sexual stimulation would please you.
Whichever approach you choose, I hope that sparks fly soon for you. You deserve genuine pleasure, you know, real beef with no artificial ingredients.