I did similar things when I started. I would go to Target and pick out a half dozen other manly or child related things then go to a line where the cashier was a younger lady. In other stores I would walk through the aisles quickly, and make a few passes before I could see the items I wanted, then quickly go to a non busy checkout counter. I found another trick in that I would make a phone call as I was browsing. The call would occupy me and I would forget the small fears. I began to thaw when I was at Ann Taylor a sales person saw me and asked me if she could clear a dressing room for me. I was in a hurry and could not take her up on her offer, but I wanted to go back. These days I have come to ease with it. I usually do not go shopping dressed. I love dressing, but I dress for night life, and do not find the outfits and contoured makeup the most comfortable for a shopping trip. My recent shopping was at MAC and Victoria's Secret for a bra. I just simply find the quickest sales person, tell them what I am there for, and that it is for me. You would not believe how simple it is.
