You can achieve a prostate orgasm even if not homosexual - you do have to be in the right mind space for it though - if you're one of those people who are "EXIT ONLY" about your anal passages then you're definitely not going to be able to and only partially because you'll instinctually clench and cause yourself more pain.
The reason that so many of the strap on and other dildos that you see which are advertised as homme toys is because like with women there are a certain percentage of the male population out there who like the feeling of being stretched around a larger object - they actually find pleasure in feeling their muscles clenching around something of a certain size. If you're experiencing pain when using those type of objects I would try to find something smaller, age won't play much of a role in it but muscle strength most definitely will.
Apparently the bext way to achieve a prostate orgasm ( I asked a few co-workers about this) is to find one of those finger like attachments and try a process called milking - rather then trying to nudge or hit your prostate find it with a more delicate touch and then try stroking it - kindof like with a woman when looking for her g-spot, a bit of a come hither finger crooking should do the trick.
One thing I should have mentioned (as in REALLY should have) is to be careful of the angle and speed at which you remove anal toys - anything with a larger insertion point then removal point be very careful not to 'rip' them out. The sudden stretching of the anal muscles caused by the quick removal of the more sharply expanding toys could cause problems. I'll try to do a bit of an image below to demonstrate what I mean.
<- this bit between the almost handle and the bit which is inserted is what I am referring to where it suddenly expands, this toy is probably ok but there are some out there with a very low angle at that point which is what can cause damage if removed too fast
Has nothing to do with size or shape but the angle. Sorry my ascii drawing skills suck monkey rump hence a real image.
Goodluck
And thankyou to those who have sent little messages saying they appreciate my last message in this thread