Hi Ronni :)
I have a question? Where are you with altitude and visiting bears? You don't have to tell me, I know that internet privacy is important. But! I thought that I was the only one with altitude coupled with Moosie's and Bear's. It almost sounds like you're standing here beside me except for those beach parts.
Anyway, this California transplant is now at 6950ft before I start climbing the hills. Yes! You are describing what some feel when changing altitudes. Down at sea-level you do not have to work as hard at breathing or using muscles... as you go up, you use more energy to do what you used to do easily before.
Eventually your body gets used to the new breathing and muscles routine. "They" say that you only notice the change in altitude for a few days. I noticed it for months, especially while I was out hiking. I wasn't sick to my tummy or dizzy or anything alarming... I just had zero energy. It was kinda' like my body suddenly weighed more.
Here's a link to a nice Wikipedia article explaining different kinds of altitude sickness. If you think that you might fall into any of the bad symptoms listed, it's time to go have your favorite brand of health care professional check it out.
You probably already know this, but just in case you don't... Up here we dehydrate quicker. Maybe try adding more water to see if that helps some of your symptoms?
Hang in there! Catherine