Some men find it easy to feel a prostate orgasm and some do not. Others take time to learn how to feel these types of orgasms with self prostate massage.
One key is to really relax into the sensations. Letting go and surrendering to pleasure seems to be a key in my experience.
This is in contrast to a normal male orgasm where one builds up the energy and tighene up just before the orgasm. Most men are not aware how contracted they become at the point of ejaculation.
It can take some time to develop the skill to fall into the energy and allow it to move thought the body leading to a full body orgasm. Self porstate massage is a great way to practice this method.
So scan the body during your practice and see where you tense up.
Another tip it to make sounds as this allow the energy to move upwards in the body. I lot of men have trained themselfes to make very little sounds in masturbation and sex. This is usually from self pleasuring as a teen. They did not want their parents to hear so they were mute.
This habit repeated again and again is caried on later in life. No man wants to be with a mute woman but most are pretty silent in lovemaking.
To learn more about how to have prostate orgasms click on the link.