Left side headache top of head, facial/check pressure/pain, ear discomfort, tender left side neck and under ear? Could I have brain tumor?

Likely not tumor. Given your younger age and type of symptoms currently displayed, a brain tumor is less likely. It depends on the frequency and severity of symptoms, but you might consider requesting your doctor to order an MRI brain with and without contrast (it provides better detail of the brain than does the ct). Sinusitis might be a more plausible diagnosis in your case.
Unlikely! I wouldn't worry about a brain tumor. Brain tumors are pretty unusual in 35 year olds. If your symptoms don't improve within a week or so, then i would recommend seeing a physician for evaluation.