Good afternoon - I'm Dr. Sara. I'm a licensed veterinarian who works exclusively with cats and dogs. I'm sorry to hear that your boy has been acting oddly. That certainly is a weird set of behaviors that you're describing. Initially I'd think of an anxiety problem, but it could also be related to a vision loss issue. Usually with vision loss they are also going to bump into objects and stall out not wanting to go up or down stairs, so watch for these behaviors. Also, a lot of times with vision loss you'll see that their pupils seem overly dilated especially in bright light.
As far as anxiety goes, I've seen plenty of dogs who are terrified of slippery tile floors especially after a fall. When I first got my greyhound there was absolutely no coaxing him onto our ceramic floors. However, over time, he learned to deal with it. We also helped by placing rugs. It's odd with your dog, though, that this has developed suddenly where he never had issues before.
Anxiety disorders in dogs can come on like this and they don't really make sense - just like people who have anxieties can't always explain WHY they are anxious about something, just that they ARE. If his vision gets tested out and it's all AOK, then I'd definitely be pegging this as an anxiety/fear issue. Depending on the severity and the course (ie: is it getting better on its own or worse over time), I'd discuss the use of an anti-anxiety medication to see if this helps calm the behaviors. They may not necessarily need to stay on this long term, but it can help them get through a rough patch. My own dog was absolutely terrified of a certain type of large loud buzzing insect that we have in our region (the stink bug). We didn't have them at our previous home but they were everywhere at our new home. He was paralyzed with fear every time he'd see one. It took us a few months to figure out what exactly was triggering his anxiety - up until that point he just looked anxious all the time for no apparent reason. He was on fluoxetine for a good six months but I was eventually able to wean him off once he'd become accustomed to the stink bugs.
I'd schedule a checkup with your vet at your soonest convenience to check him over and discuss either training routines or medications to help him through this rough patch. It's not likely an emergency if he's still eating and drinking OK and looking healthy otherwise.
Please let me know what other questions I can answer for you - we can chat until we've covered them all.