I have had a fever that goes up and down drastically for 9 days now. Usually it spikes at night going up to 103. Then it quickly drops with medicine and I wake up drenched in sweat. I have no appetite and a constant headache. Some nights I vomit some I don't. It started with severe back pain and a stiff neck. I have no spleen so I don't know if this is making it worse.

See your doctor for proper diagnosis. The stiff neck and back pain may indicate something serious.

I just moved so I went to a new doctor he didn't seem concerned just said it can last up to 10 days, and come back later if it doesn't go away.

Sounds like you went to a bummer of a doctor. If the problem continues, find another doctor, preferably one that is "concerned", "interested" and willing to find the cause of the problem.