I feel a need to jump in with a different perspective.
It is entirely normal, and entirely in keeping with how Hashem made man, for men to experience unintended arousals, wet dreams, etc. To experience guilt over these events (mark that word: the events themselves) is simply inappropriate because man has no responsibility and no ability to exert conscious control over the unconscious event.
I'd say this applies millions of times more for a teenage (under-age) kid. (The "sins of our youth" include these actions and are completely forgiven by Hashem on our 20th birthday, as I understand the halacha.) I would suggest you consult your Local Orthodox Rabbi on questions like tumah-&-keri, mikveh, etc -- these may be embarrassing questions at first but if you can somehow forge a personal relationship with a Rav/Rebbe for these questions I expect you'll have an easier time dealing with issues like p**n etc.
But this is NOT a halachic matter here: it's a biological one.
I think many of the post-ers might be forgetting that you are a young teenager going through intense concentrations of hormones, exposures to new thoughts and images, and many other considerations that do not apply so heavily to a man with more years under his belt (ahem) to guide him. You've got a hard enough (ahem) time dealing with your body, the images that surround us in Golus, the thoughts that creep into your head from who knows where, etc. Please don't add guilt onto every wet dream. You're doing fine.
Now, as to the issue that you might be promoting these EVENTS with your THOUGHTS or actions during the day -- well, that may be possible. I don't know. If the dreams are proportional to improper thoughts during the day, it may be a siman to work on the thoughts. But I feel as if you've already posted that your machine is filtered, you want to stay away, you ARE staying away, well... I'm just not convinced that your daytime actions make you chayav for your nighttime events.
As to the other forms of embarrassment you allude to (I assume you mean the details of cleaning up, whatever), these surely have pragmatic answers. Feel free to PM for ideas but you probably don't need them.
And as to anyone suggesting in any post that a wet dream makes you a sinner, an addict, a lewd person, etc - shame on them.