Internet speed impacted after downloads

Hello,

I did some torrent downloads, and now my internet connection intermittently drops out. I ran fine for almost 18 months with no hint of this problem and I started noticing this the next day after I stopped downloading. I have called my cable internet provider tech support several times, but they are generally clueless. Frankly, its amazing they can even find their way to work every day, but I guess I don't hear from the ones that don't. Anyway, high on my list of suspicions is that (1) Time-Warner cable downgraded my service because I actually used it, or (2) someone somehow got my ip address and is punking me possibly either related to torrent downloads (querying my ip to see if I am available to share a file), or some anti-file sharing group pinging me in retaliation for using torrents, (3) Its not a cable-monopolistic conspiracy but actually a shadow government conspiracy that only Molder knows about.
I am leaning more towards #1 above since my upload speed is disproportionately affected. Has anyone else experienced similar or has can suggest how I can test my problem or my suspicions?