I think your mind has spun out thinking your T will hate you rather than being proud of you! You took care of yourself in an, obvious to me, necessary, way. Whether the guy meant to invade your space or not doesn't matter; he did and you responded appropriately for you! That's what it's all about. There were only a couple things you could do in that situation; either back away yourself (when it was he who was moving into your space) or block him and you used the tool at hand, your grocery cart, and blocked him. I say, good work!