Jeff, have you thought about using a 2 meter J-pole antenna? I used mine for a while just sitting in my bedroom window, and have excellent results. They're thin and pretty unobtrusive. You could even make a J-pole for your HT with a length of 300 ohm twin lead (like we used to use on TV antennas). A google search for "roll up j pole antenna" will give you lots of options for an antenna that you could easily pin up in front of a window.
For less than $20, you can get a small mag-mount mobile antenna for the Baofeng on Amazon, and put it in the middle of a shallow metal cookie sheet. The cookie sheet performs like a ground plane, and will help.
I would also take the Baofeng outside and walk around some with it, just to see if the problem really is poor indoor signal. Maybe try the rubber duck and the Nagoya just for a comparison.
Just a couple of ideas....I hope you don't give up on it
