I Think I Have a Small (internal) Hemorrhoid, What Can I Do To Get Rid of It?

A couple days ago I was in the shower and I noticed a small bump in my anus. So I pushed it back in and checked it out in the mirror (this all seems rather questionable and nasty, but stay with me). The bump was (and still is) roughly the size of my pinky nail, and just peeking out. The past few days, I have experience absolutely no pain, and it never comes out very far. I just slip it back in every time I take a shower and it doesn't bother me for another 24 hours.

Is this a hemorrhoid? If it is, how can I get rid of it, or prevent it from getting worse? Should I avoid sitting down for long periods of time? Should I continue pushing it back in? Will it eventually completely fall out? Will it grow bigger? Will I eventually feel pain? Should I change my diet? Is there anything I did that caused it? Thank you in advance.