What prescription can help decrease SEVERE anxiety before shots / bloodwork ?

I nevous aroudn sharp things. For the dentist I take 2 0.5 mg of lorazepam before a cleaning or filling. For shots in my arm I need more that that. I will take 2 1mg pills of lorazepam prior to the shot. I took 2 of the 1 mgs before i was supposed to hav blood taken today to calm me. It didnt work. I need something more potent as my fear is deep seeded (b/c of a medical procedure at 4... almost 18 years ago.) I've tried visualizations and self talk, but I need drugs to help me do this. Please no smart mouthing as I go tomorrow to have my blood taken (I was supposed to go today but chickened out even with 2 1mg pills in my systerm). PLease help me, I'm at my wits end with this phobia.