The pulling tight sensation in certain positions sounds like scar tissue, probably from your surgery. This may well improve with time.
I have a pelvis full of adhesions following being left with appendicitis for 3 weeks, and the discomfort became less and less over time.
Once fully healed, an active lifestyle can really help things soften and stretch out.
However you are on a low dose of systemic estrogen and also blissel is less than one tenth of the strength of regular vaginal estrogen creams, so atrophy is highly likely.
I would seek help for this rather than just putting up with it.