Could I have had a silent heart attack? A few weeks ago I experienced severe pain in back, chest pressure/pain, lightheaded and dizzy with nausea.

Not by what you say. A silent heart attack is one that has no symptoms, so whatever it was you experienced, it was not silent. Was it a heart attack? I'm not able to say for sure, but i tend to doubt it. An ekg might help answer the question. You are taking medications for blood pressure, so it would be wise for you to discuss this with your doctor.
Silent mi. Truly if at all, it would not be "silent" because you had pain. Being 33, it would be on the young side for having a heart attack, but without an exam and at the least an ekg it would impossible to tell you that what you experienced was due to a heart condition. Get checked to be safe, best wishes.