Is Lost Of Balance, Headaches And Shortness Of Breath Be Sinus Infection?

Hi... i started feeling bad the middle of april... by the beginning of may it still wasn't better so i went to the doc and they said it was a sinus infection. They gave me some zyrtec... i week later started feeling like i was going blind... everything was blurry. A few mins later i lost my balance. It felt like my feet and legs were trying to pull out from under me. Then i started having slurred speech... i went to the er and thery did xrays but found nothing... .but did say it was all the symptoms of a minim stroke. Ever since then i have horrible headaches and shortness of breath,. They did a pft and said it was dyspnea...... could this be sinus infections... please help me...