Bricks, Masonry, Asphalt and Concrete - How do I fix the potholes in my concrete floor?

I want to VCT my garage floor, but the concrete is mess. I actually have potholes in my floor. In one area the hole is so deep that I have discovered something, which has sent me here to post a thread. It looks to me as if at one point someone tried to build up the concrete in one area to make it level with another. The fools did this by placing OSB down over the lower level of concrete and then pouring more concrete on top of the OSB. This whole area of floor is where the potholes are developing the fastest, and when you walk overtop of the area it feels almost spongy. Does this whole area need to be torn out and repoured ($$$), or can I patch floor and self-level it? Of course want to do this as inexpensively as possible, but I don't want to put VCT down and then have it start coming apart because the concrete underneath is still degrading. Or perhaps I could patch the floor and put DryCor down, would that work?

I wouldn't put the tile directly on top of the concerte. I suggest at least 1/2 inch plywood or something similar as a subfloor after you patch the cement. Remove what's lose first. Patch the cement and fasten the wood with hilti shots or strong anchors.