SHTF stuff is funny. It's kind've like asking, "A guy tries to fight you in a bar, what do you do?". Your reaction is going to be completely dependent on the situation. You can try to increase your odds through training to give yourself more options on how to quickly react, but trying to say you'd do one thing or the other is just pointless mindplay. Your reaction will be different if the guy charges you with his head down, swings a haymaker, tries to get you with a front kick, or breaks a bottle to cut you with.
In one scenario, I'd be working behind the gun counter at basspro. I live all of 2 miles from there, so it'd depend on how rapidly things deteriorated if I could take advantage of being around lots of survival supplies or the more likely scenario of me just getting sent home early. If I was sent home early, I'd be trying to communicate with my fiance and would try to swing by the safeway to see if they were open to stock up on some more long-term food. Last time we had a big storm that knocked out power for a week, it was funny to see all the canned and dry goods readily available, while frozen foods, milk, water, and things you'd have to refrigerate were all sold out. After that attempt, I'd try to top off the gas tank and go home to try to communicate with my family. My m&p9c would stay on my hip and the ar would be in the same room as me, and I'd check over my food. I'd clean the tub, then fill it up with water. I'd check medical supplies, ammo, and lube the firearms up. I'd essentially be checking and rechecking things while waiting for my fiance to come home. From there, it's very highly dependent on what exactly happened to determine if a motorcycle ride would be in order or if i'd just ride it out at home.
If it happens while I'm teaching, then I've got to think of my responsibilities beyond myself. It'd be my job to keep all of my kids safe and manage the panic as parents flood into the school to try to snatch up their babies. Our emergency plans would go into effect and I'd have to do my job until all my kids were safe. Eventually, I'm hoping they'd be all picked up and then I'd get a late start trying to get home. Getting home may involve walking depending on the state of things, as the delay would be a pretty big handicap. The general plan would be the same as above once I got home.
trying to speculate beyond that is silly to me. I do attempt to learn as much as I can about all things to become self-sufficient so I can give myself as many options as possible to respond to whatever comes up. I'm trained in rough medical care, auto mechanics, woodworking, orienteering, firearms, food stuff, fighting, and a bunch of other goodness that would come in handy. Im always trying to better myself to be as useful as possible in any situation.