Dog behaviour changing since new furniture

[DnA]

We have a beautiful 8 1/2 year old male Shepherd cross who has always been a bit nervous. Examples: He's terrified of thunderstorms, will jump at sudden noises or if something moves close to him, he doesn't like going in strange places (took us an hour to get him in our new house 7 years ago) and he's very cautious with eating.

We've known about his little quirks and love him all the more for it, but we bought new reclining sofas in November and he got really nervous when we would recline (they're power recliners, so make noise) and wouldn't come near the furniture. At the same time, he started acting funny with the laminate floor, and would NOT come into the kitchen at all for weeks. We had to move his food and water out of the kitchen. It's almost as though he's forgotten how to walk across the floor. He gets all worked up and starts to slide, so he gets more scared and it deepens his fear. He's totally okay with the furniture now, but he's still scared of the floor/stairs. Some days he won't go up or down the stairs without help, and unfortunately, encouraging him seems to make him more nervous.

We've covered up our beautiful new floor with rugs and he seems happier, but I can't cover it all, and I'm not sure why he all of a sudden became afraid of the floor when we got new furniture. He was fine with the flooring until the new sofas arrived. When we saw the vet 7 months ago, he said he was healthy and doing well for his age.

Any advice or help would be appreciated. Thanks!