Isolated diastolic hypertension was anyone successful in treating it

I have an isolated diastolic hypertension where my systolic blood pressure is normal but diastolic is elevated, it’s been difficult getting it under control since the meds I tried also lower the systolic pressure too which caused me to feel dizzy and even fall, my doctor doesn’t seem to success in lowering only diastolic BP.
I’ve been on a plant diet for about a year now, and exercise moderately. But nothing lowers my diastolic BP which ranges between 86 and 100 with the systolic BP always under 130. Any feedback would be appreciated!