Hi Angela,
I'll second the comment about taking a moment to just breathe! : )
Everyone's ideal itinerary is unique. Describe in just 1-2 sentences to yourself, what do YOU really want to do on this trip (not specific locations, yet), i.e. "This trip would be ideal if I could see Italian art galleries, leisurely walk through a small village & have a glass a wine with a view, hike in the mountains and experience a non-touristy town. " Then, write down each of your current locations you're considering & briefly note - city vs. village, evening possibilities, daytime priorities, mountains/water/other. Do you see a gap between what is important to you & what's on your current notes?
Next, my recommendation would be to go to the www.rome2rio.com site, input your destinations and see how long it takes between locations + plus, look in their view map for additional locations with good connections between what you're planning. Personally, I only want a couple of days where I'm on a train 3 hours during the entire trip to maximize our experience.
I just finished our itinerary and we'll be going to Lauterbrunnen/Wengen, Stresa, Florence, Siena, Grosseto, & Rome. Some are repeats to spend more time there. We haven't been to Stresa, so I would love to hear how you like it.