Thank you for the query.
What you have noticed is a hemorrhoid
indeed. It gets painful when a blood clot appears inside.
It is impossible to palpate or even see a hemorrhoids which are inside the anus. It is because when you press them, it simply collapses. Hemorrhoids (if not external) can be only seen in the rectoscopy.
Also bleeding does not have to be present. It appears when hard stool tears a hemorrhoid.
Usually hemorrhoids do appear because of lac of physical activity (sitting for long time), pushing hard on stool, constipation
or due to pregnancy
(uterine compresses veins in the pelvis).
To improve your hemorrhoid, you should: increase fiber rich products and mineral water intake, do not push hard on stool, use OTC hemorrhoids suppositories, have sitz baths with Quercus Cortex
twice a day, wash your rectum
after every stool. Such treated hemorrhoid should improve in a week or so, but it wont disappear completely. Sooner or later you will have to ask for surgical removal of it.
Hope this will help.