Dear friend, welcome and thanks for entrusting your query here at HCM !
Your BP numbers are acceptable since you are on treatment.
Do you get any dizziness
or blackouts, especially on getting up from lying down?
BP fluctuation is normal with day to day activities.
Low diastolic(bottom numbers) BP is either due to vasodilator anti-hypertensives (BP medicines) or weak heart on 2D Echo.
Please mention all your medicines and post your last post-surgery 2D echo report to answer your last question precisely.
If you have no symptoms now, do not worry about these.
But keep regular check-ups as advised.
I hope you are fully satisfied with the guidance I gave.
I would be glad to answer any further queries.
Thank you and Good luck !