No you should be excited for the 6 and don't question your decision. I'll break down the supposed 3 spec upgrades on the 6 Plus compared to the 6..
1. Screen resolution... In all the hands on the difference between the 2 are not even noticeable to the naked eye. The 4.7" screen does not need 1080P, all it would do is drain the battery quicker.
2. Battery life... Either way you will need to charge both phones or top them off once a day if you use them with any regularity. Even more so with the Plus because you will be tempted to watch more videos, etc on it because of the larger screen therefore draining the battery quicker. Besides, my iPhone 5's battery is fine and the 6 is even better so I'm satisfied.
3. Camera... So the Plus has IOS and yes that is a nice feature but to be honest my 5 took amazing pictures and once again Apple has improved it even further with the 6. And if I am going on vacation or somewhere where I want amazing pics I have my Sony NEX-6 for that.
In summary, these small improvements over the 6 is not worth giving up portability, better pocketability, better one handed use and just a better overall feel in the hand. The size of the 4.7 seems to be the sweet spot IMO when it comes to a phone and everyday use. I have my iPad Air when I need a "big" screen.