Pressure in left temple, behind the eye and down the left side of head behind the ear. Tight muscles in neck. Allergy meds having no affect. Ideas?

Head pain. This could be a headache condition such as a muscle tension headache or a migraine, but much more detail is necessary. Other possibilities might be myofascial pain from clenching or grinding your teeth. Sinus/ allergy conditions would be less likely based on the information provided. Lastly, other conditions such as trigeminal neuralgia or temporal arteritis could be considered. See MD for help.
Not allergies. Sounds more like tension headache- talk to your primary care doctor about this.