Do I have the flu or something different?!

Sounds to me like the Flu, or else just a really nasty cold. Either way, there's not much you can do except stay comfortable, and wait it out, since it's a virus. I would suggest over the counter pain killers (Aleve) to help with the throat and muscle aches, lots of fluids (vitamin C- and LOTS of it!), and SLEEP! The aches and drowsiness are signs that your body is working hard to beat this, and the best thing you can do is provide it with the rest it need to do so.

One thing gets me though-- Usually cold/flu related muscle aches are spread throughout the body, not just specified to a single area (the deltoid muscle, in your case). Is it possible that it is from an injury, or from physical activity? Often, things like that take longer to heal while a body is sick.

Either way, at this point, I doubt it's anything to worry about, especially if you're young. Since I'm not a doctor (yet!) I would suggest seeing a professional, just to be sure.

Medical Science student.

Its the flu

I'm not so sure because I am not a doctor but you might have a cold.