I'd be heading to the E.R. right now. (I've had antibiotics and experienced pneumonia, and been admitted to hospital for it.)
Levaquin has a crummy record. It often causes terrible muscle pains and discomfort, lasting for months. You need to go back to your doctor. Cipro, though a similar medication (a fluoroquinalone) has fewer side effects.
As you are having difficulty breathing, then you do need an urgent appointment to see your doctor.
To help loosen up the congestion and unblock blocked sinuses, do steam inhalations.
To do steam inhalations, boil up a kettle full of water and pour this into a bowl taking care not to get scalded. Put some Vick or Olbas oil or any menthol drops that you have into the hot water. Bend your head over the bowl and cover your head and the bowl with a towel. Breathe in the steam through your nose and out through your mouth. Do this for around 10 minutes and try and to it 4 times a day. Do this for as long as you need to.
Even if you are not able to do a steam inhalation 4 days a day, doing some is better than none.
Make an urgent appointment to see your doctor, or go to the Emergency Room of your hospital if you are struggling with breathing.