Lube shop installed small filter, now my engine burns coolant and oil like nobody's business

Two comments as follows:

It is difficult to believe that even a careless person would send a car away with an air filter that fits as obviously bad as you describe. That would guarantee a trip back to the Texaco Xpress Lube place with a complaint.

Back in Model A Ford days before air and oil filters came into use, cars could make it to 30,000 miles to a major overhaul. These were driven much or even most of the time on gravel roads. 400 miles on paved roads would not be enough to do your engine in, not to mention that part of the intake air was, after all, filtered. Not all of the air will bypass the badly fitted filter.

Either the original post was a troll post or else the engine was far along on its way out before the servicing.