Old bike 650c, New bike 700c?

[Geonz]

I'd say give it time. I haven't done it both ways but I'd expect a bit of adjustment.

[BleeckerSt_Girl]

Yes, give it a couple weeks to get used to the "high" feeling. I felt very "high up" but I got used to it and now it feels like nothing at all.
As to whether your wheels are "too big": First, I am assuming you can stand over the bike ok when you are not sitting in the saddle, right? Ok then, so the top tube (if you have one) is not too high. You should NOT be able to balance with both feet or toes touching the ground while you are in your saddle. If you can, that means your saddle is too low and your legs will always be too bent while you peddle. It's not so much about the size of your tires as it is about your seat height. The bike height difference with 650B vs. 700c tires is not THAT great (remember only the axle-to-ground distance counts there, not the total wheel diameter -which counts the tire thickness twice). What makes your feeling of being "high up" is mostly A)the size of your bike frame and B)the seat height on top of that.
You can change the height of your seat somewhat, but you can't change the height of your pedal crank axle. So changing your seat height will change how much or how little bent your leg is while you pedal. People with their seats too low and their legs too bent wind up with painful knee problems if they bike regularly. Plus they can't get as much power from their pedaling.
Give it a week or two before you try to change it. What feels wrong now may simply be because it's new and different. It was to me, anyway, and now I am VERY comfortable and I laugh at what I thought was "too high" a few weeks ago.