I Am On 10mg Ramipril For 5-6 Years But Have

I am on 10mg ramipril for 5-6 years but have been experiencing low diastolic in 50-60 range for several months and am embarking on process of lowering ramipril to see if this will be better. Dr has given me 2.5 and 5mg tablets but no instruction on how to proceed with titration, any advice please. I went to 7.5 for a few days but diastolic still low and still causing occasional balance problem. so have been on 5mg for a few days but am concerned about whether I am tackling this safely.