Well first off I'm going to suggest that your frame is too small. Depending on how you measured it a 21 inch frame is only a 53.3 cm size. That's fine for a mountain bike that uses a radically sloping top tube but road bikes are a whole other enchilada. I'm 6' 1" as well and the SMALLEST road frame I ride is a 58 cm that just happens to have a long top tube so it fits nicely. Unless it's one of the sloping top tube style frames (hard to see for sure from the picture) with a long top tube and a larger effective seat tube length then I'd say that this bike is too small for you. I'd say that you should go along with what the others are suggesting and get you and the bike into a proper road bike shop and have them size you up and set up the bike for you. At the same time they'll be able to confirm if the frame size is suitable for you. Because from the picture it sure looks to me that you must feel like a size large guy trying to fit into a size small Speedo.

Before you run in for the bike fit look at some other bike pictures. For example touring bikes use the same sort of bars and levers and the riders find them comfy for man hours at a time. But the key there is that for a touring rider they use a stem that puts the top of the bars up much closer to being even with the top of the saddle or even just a hair higher than the saddle. Asking for your riding position to be set up more similar to a touring bike may be something to consider for now. Then later if you find you're becoming more aggresive in your riding you could get it re-fitted for a lower bar position so you're more aerodynamic in the saddle.

But none of this alters the fact that this bike could well be too small for you. That's the first thing to find out. You could google for "bike fit" or "bicycle fit" and find some articles. If it's close there's some room to play with and at least you'll learn what all the terms are and how to measure the effective top tube length.