thanks, this decision took over a month to make and, in the end, after accepting that I had an adequate "picture" of the hard drive (having used Time Machine with my external hd) I decided to wipe the drive and the system. Wasn't easy but it was a question of dealing with problems every day or taking the chance it would work.
i restarted while pressing cmd r: the computer shifts into the recovery utility. i went into the disk utilities and chose Erase.
after that i went to the file menu ad restarted my machine. this is a different step than my first time restoring.
the first time i went to the recovery menu after erasing my disk and reinstalled. this reinstalled Yosemite.
the difference on the 2nd time around was, after erasing the hard drive i restarted the machine. it took me to Internet Recovery and then to a similar Recovery utility as before.. this is where the program set up the original OS that came with the computer.. so mine was Mountain Lion.
after it set up and the system was running i went into the app store and downloaded Mavericks from my previous purchases.
hope that keeps it simple, I'm no computer dude either, but most of my questions and problems I was able to look up with Google and read a lot, and from multiple sources. Good Luck, the only constant during [my only] problematic times with this computer were when Yosemite was present, that was the line in the sand for me. Just make sure you know you have everything you want in terms of personal data. so far tho, no problems with Mavericks and great for the daily grind - having a secure system takes away daily anxiety about what process would kill what next. now I can get back to work. smoke weed.