Hi Brenda,
I was only on AConce, in October. We did not encounter any strong currents on the dives I went on. We also dove at Turneffe (Spelling?) which was amazing.
There should be an anchor line that you will be able to go down slowly to clear your ears. Just don't let anyone rush you. You need to be comfortable in order to be able to enjoy the dive.
As others have said, Amigo Divers is good and will be able to help you out.
When I get stressed before going diving, I usually try to snorkel the day before a dive. You are getting your face in the water, breathing through the snorkle, getting used to breathing throught your mouth. I find that helps relax me before going out on a dive. Even if it is just off the beach, that might help you out.
JoAnn