My last day of work is today and I am not going to go even though they expect me to be there. The HR person asked me to bring in a letter of resignation on my last day so that all the fine details can be finalized.

I have tremendous anxiety about going in and handing-in my letter because I am afraid they'll be angry/annoyed at me for skipping my last day. I am extremely avoidant, so I've thought of just leaving my letter on the receptionist's table on Tuesday (next business day). 

Now that I've typed all this up I don't really understand what I'm afraid of. I don't know, I'm very anxious nonetheless. 