I'm sick but I don't know what I have.?

I always have these weird feelings in my brain. They are so random. Sometimes they are painless, like a twitch. But, other times, I get these pains that make me stop in my tracks and wait a few seconds until it's gone. And more recently, I have developed a cold, with nasal and chest congestion. There is mucus deep in my lungs; I can feel it rattling down there. I've had a pretty severe cough for a while. When it started, I did not have any sinus problems, just the cough. It went away for about 3-4 days. Then, I developed the cold and now I have all these symptoms that don't even seem like they relate to one another. On top of all that, I have the strangest headache. I know I have the headache because of the sinus pressure, but there's a little more to it. Every time I sniffle (even the tiniest sniffle) my head hurts. I can't tell what the feeling is. It either feels like it's about to explode, or it feels like my brain has a giant cramp. I can't tell. Every time I bed forward, it feels like all the blood is rushing to my head and all the sinus pressure rushes to my brain. It's painful and it makes me feel like I'm going to p out. Now I'm just sitting here being still and every so often I get this pain in my brain that makes me cringe. It lasts a gseconds. My eyes feel like they're going to shut down and stop working. Sometimes I'm sitting still and it feels like my brain is leaking, like it's dripping. I'm so confused. I just want to know what exactly it is that I am experiencing. Pneumonia? Bronchitis? Pleurisy? Is something wrong with my brain? Do I need an MRI, CT or something?