med error

I made an serious med error recently and I am having a hard time getting over it. I have been an RN for 2 years and was recently laid off of my job. I was called in to work a midnight shift and at the end of my shift I was in a hurry to go home. My pt. was supposed to give 26units of lantus insulin and I gave regular insulin instead. the terrible thing is that I had another nurse verify the order and she just checked the dosage and order on the MAR and not the name on the insulin pen as I had my hand over the name not realizing this at the time. I don't know how I could have done this as I have given these two meds before many times without a problem. Needless to say I had to call the MD and nursing supervisor, also appoligize to the pt. and spouse. Got new orders from MD, have an IV put in and monitor VS and BS hrly. I had agreed to work for another nurse on this unit today on afternoons before this happened and now I am afraid to even go to work. I need advice please!!!!!