My head feels like there's pressure building, then I get waves of dizziness, symptoms go away when ears pop, what's happening? Had ear tubes long ago

Keep them popping. It sounds like your eustachian tubes are not venting your ears until higher pressure has built up. Pressure in the middle ear pushes an oval membrane that separates the middle and inner ear. The inner ear has 3 tubes filled with fluid that help your brain keep your balance. When pressure is put on that fluid it confuses the brain and causes the dizziness. Popping helps releases the pressure.