Severe pelvic/rectal pain + constipation after anal sex and period. MiralAX helping but still in a lot of pain

F22
I’ve been dealing with sudden constipation and significant pelvic/rectal pain over the past few days. This started about a week before menstrual cycle and about a week after anal sex.

Current situation:
Constipation started a few days ago (likely hormone-related). However I always have struggled with chronic constipation.
I’ve had painful bowel movements since then
Now having constant pressure/aching in the perineal/rectal area with burning sensitivity, worse when sitting or going to the bathroom
Still able to pass stool and gas
No fever or vomiting

What I’ve tried:
MiraLAX (currently using)
Stool softeners
Ibuprofen
Warm baths
I’ve been evaluated by a doctor and nothing abnormal was seen externally.

My main question: has anyone experienced severe rectal/perineal pain with constipation that ended up being pelvic floor spasm, fissure, or stool-related pressure? How long did recovery take and what helped most?