Don't feel very metal anymore?

I like to think that I've been a pretty devoted metalhead for the last 4 or 5 years, but lately I feel so bored. I used to listen to death, thrash, and a bit of black metal for hours a day, but I just don't feel it anymore. Recently all I've really been listening to is stuff like Melvins, Neurosis, Isis, and Mastodon. Honestly I feel a little nervous about this change; it feels a lot like I'm losing a part of myself and struggling to find anything to fill up the void. Has anyone else experienced this or have any advice for me?