What Causes Dizziness And Stomach Discomfort?

when I spend energy by working in the yard I feel weak and get dizzy. My stomach also feels uncomfortable and I may need to go to the bathroom. I have a numbness across my shoulders and back of my neck. I sit down and take a little rest and then go again. Not for long because it comes on quick again and worse than before. I have had stress test within 6 months and echo s of arteries, heart, EKG every time I see my hart doctor with no bad symptoms. I have not had these symptoms before I had my medication changed 6 months go. My blood pressure medication was changed along with my diabetic medication. I take my blood pressure 3 times a week and my pressure the last six months has decreased to a sys average of 125-135. My diastolic average of 55-65. pulse 58-64. About 3 hours after I take my meds I start feeling a little dizzy and numb all over but not the way I feel when working outside. I sometimes have to lay down because I have no energy. My arms, lower back ,shoulders, back of neck all feel very numb. I have had two of these episodes in the last couple of months. Those scare me because all I can do is lay down until it passes. I feel the new meds (more aggressive) are doing this to me. Your suggestions/