I want to start off by telling you that it’s a good thing you found a way to redirect your dreams of sex by some means; concerning your new kind of dreams, let me reassure you that it is also normal. Pornography is a double edged thing: it helps to alleviate needs and/or fantasies of people, but on the other hand, it opens new doors to your sexual life. I mean that it eventually leads to your subconscious mind creating everyone around you, even the most unlikely of people, into an ‘actor’ of what you watch in a porn video.
Also, the forcing aspect that comes up in your dreams could signify many things: as dreams often do, maybe something in the personality of your friends could suggest them to a more ‘rough’ side in your dream, or maybe it’s the proximity you have with them that tends to make them the sole actors of your dream. Friends are frequent subjects of ‘taste’ in such kind of dreams/fantasies, and more often than not men/women dream of intercourse with their father/mother (think Oedipus’ complex…).
It’s possible too that when we stress over or ponder our dreams excessively, that this could provoke even more dreams about the subject we are worrying about.
I do hope I took your question correctly, but don’t hesitate to requestion, we’re here for that very purpose!
Good luck to you,