You have sustained a minor head injury a month back but, fortunately, there was no severe repercussion. Getting your eyes evaluated by an ophthalmologist to ensure no damage to the retina inside the eye was a sensible decision as well. When astigmatism is diagnosed, it means the eye has a refractive error in only one meridian. Hence, things like a point source of light, letters like H and N look really distorted. Light, particularly, seems streak-like in nature and the glare is particularly debilitating. You already have a myopic refractive error of -7D so that is probably worsening your situation. Uncorrected refractive errors or inadequately corrected ones particularluycylindrical errors (astigmatism) can cause dizziness, objects appearing tilted, nausea, constant headaches ,eye ache and blurred vision such that, after a while, it seems to remain constant. You have a history of migraine that can be aggravated with this scenario. Please have your refractive error checked and wear the right spectacle prescription all the time. Try a little rest for a couple of days and use ice packs on your eyes as well. Most problems associated with an uncorrected astigmatism disappear in a week at the most.