how to not feel angry about the things i imagine

in my lonely flat, i tend to think deeply and fantasize about other people's lives, and i thought recently, what if when i die, that girls and men get off on it sexually?...they have erotic sex in a doggy position getting off on my demise and death?

and i felt really enraged at those people by thinking of that, with the strong urge of wanting to get aggressive with people, because of what i imagine they would do after my death?

i know it's a really bizarre perverted thought, but i have all kinds of thoughts daily, which i try to dismiss and not think about.....but its hard, especially if you don't have a girlfriend at the moment like me, because you deal with mental and social problems.....but i really want to overcome them and achieve the goal of finding a partner....but until i do, my fantasies run away with me a lot, especially about others in society.....and wishing i had what they have or what they possibly experience.

any thoughts on how i can deal with this?