No longer able to get horny?

I recently turned 23, graduated from college, and now work full-time. I live with my boyfriend and our good friend. Since spring semester and graduation, I have not been able to get horny whatsoever. I've tried masturbation, lubes, having my boyfriend try things on me, porn, everything. I don't know if it's stress or adjusting to my new life as a college grad but I used to be able to get horny with no problem. I'm not supper bummed by it, but I wish I was back to "normal". Has anyone else experienced this?