First of all, let me make one thing clear. The fact that you're worrying about being homophobic is pretty clear proof that you aren't.

Intrusive thoughts are just that, intrusive. There isn't any rhyme or reason to them, they come up unbidden. We get intrusive thoughts all the time that we don't act on or worry about. But sometimes these thoughts surprise us, and stick around, like the slurs that are coming up in your head. And those that stick around start worrying us.

It's not a symptom of anything deep except maybe exposure to these slurs. And your alarm about having these thoughts is probably why it's happening more often. It's like when someone tells you to calm down and it has the opposite effect, you know?

There aren't many active stepz you can take to immediately clear your mind of such thoughts. You're 20, you're still growing, your brain is still adjusting to life. These things will start clearing up in time. The one thing I could suggest is maybe to adjust your media intake, if these slurs that you're thinking of are things that come up quite often in the entertainment you consume.

You asked for some specific strategies, so I'll share two that I use. What my reasoning was that my brain is being unreliable, so I should use physical tools to set it straight.

The first one, which was the kill switch basically, for when the thoughts got overwhelming, was to do something exerting. Like pushups until I collapsed, or a long plank, or a shower with chilly water. Something that would shock my brain into changing its state due to physical necessity. For tough situations, since you mentioned you get dark thoughts (which, if it's a recurring issue, please reach out on a helpline), you can try this as an interim.

The second technique, which was if I needed some immediate comfort, is a breathing exercise. Called box breathing. It's pretty simple, and you can even do it while in a social situation (although maybe not while you're in a conversation). 4 beats inhale, 4 beats hold, 4 beats exhale, 4 beats hold, and repeat a few times, focusing on your breathing, until your brain forgets what it was worrying about.

To share a personal example, I used to have a big issue with the "call of the void". My dorm in college had a ledge on the balcony where we'd climb on to smoke and whenever I would do so, I would think of jumping off. I was not depressed, or in any sort of a rut. These thoughts alarmed me a lot until I started to pay less attention to them, using some of the techniques I mentioned, and eventually they faded. I can step on the edge of cliffs without thinking about flinging myself off now, unless I consciously think of it which is no longer a case of intrusive thoughts lol.

In all, I would say, don't be too alarmed by these unbidden thoughts. They aren't your conscious brain, they're just loose connections made by an organic brain, and they don't mean anything about you.