Lisinopril Problem?

59 year old male taking 30mg per day. Been at that level for a few months. Recently developing cough, headaches, lethargy, dizziness and over-all crappy feeling. Missed a dose for a couple of days and felt pretty good. Am I having issues with this drug? My doctor doesn't ever seem to have the time to really talk about it and I'm getting scared I'm on too high a dose. Can I self drop to 10mg /day? My bp, though elevated is not all that bad. I can monitor this closely myself I think. What to do???