Hydrochlorothiazide for Pulmonary Hypertension?

I started on Hydrochlorothiazide (25 mg - per day) for Pulmonary Hypertension on June 10th. I felt unbeliveably good for a week and a half and now for the last 6 days I'm back to feeling so tired and my legs feel heavy - as they did before I started the medicine. I called my doctor and she said I'd have to wait to increase the medicine until I see her July 14th. I'm just wondering if anyone else has had this experience and if you felt better when the dosage was increased - and did you continue to feel better from then on.