If, specifically, you want to cover telephoto and macro, and not necessarily general-purpose nearby photography or wide angle shots, then yes, this is no problem, because relatively long focal length macro lenses are a common design. Sony, for example, has a 100mm f/2.8 macro lens. This won't quite give you the reach of a more extreme telephoto lens (the kind used for professional sports or for wildlife), but should be very sharp. It has a minimum focus distance of 35cm (14"), which gives it a true macro magnification: objects will be as large on your sensor as they are in real life.

You may already know all of the following, but just for some background....

Long focal length is generally thought of as giving the ability to photograph things far away, but really it just tells you the angle of view the lens covers. Higher focal lengths give a narrower view, which translates to rendering far-away details larger — but it also means that close-up details are larger. However, most lenses with high focal lengths can't focus on objects which are nearby, just as an inherent limitation of their design. Lenses which are made to be macro, however, are designed so they can. (See this answer.) This allows you to focus on close objects (such as the details of a flower).

That same lens will also be useful for general-purpose distance shooting, including portraiture, although with your APS-C DLSR it may put you a little further from subjects than is ideal for everything but the closest headshots. If the Sony lens seems out of your price range, you could also consider the Tamron 90mm f/2.8 macro, which is noticeably cheaper and also well regarded.

In combination with your existing 18-55mm (or an eventual upgrade to it), this should add a lot of versatility to your toolbox. You can use the 18-55mm for general use and wide angle, and this lens for more far-away objects and for macro.

If, on the other hand, none of the above sounds right to you and what you really want is a single lens which can do everything... well, there's really no such thing, but you can get "superzoom" lenses which go from super-wide to very long. These generally don't have the ability to focus nearby, though (so no macro), and they have a multitude of other drawbacks, including slow aperture and significant image-quality compromises.

It's also important to note that 100mm gives you more "reach" than your current maximum of 55mm, but isn't dramatically so. If far away is a priority over macro, you might want to instead get a different lens with a larger focal length, and then get a separate macro lens or (as you note you can't afford that right now) consider alternate techniques for getting close focus.