As another newbie with less than 20 dives, I think you should reconsider your decision to dive wet. I dive in the Pacific North West where the water is cold. I've never dived in anything but a drysuit. Sure, the drysuit adds complexity to diving, but like anything worth learning, you have to keep working at it.
I've had a few issues with drysuit buoyancy as well. Nothing serious, but enough of a concern that I did a pool dive last weekend to work on my skills. I figured out what my problem was and I feel good about the accomplishment. I'm looking forward to diving next weekend.
I'm sure there are more advanced divers that will comment on your problem, but from my [limited] experience, if you had enough air in your suit for your buoyancy to be upset that much, you had too much air in your suit and you're probably wearing too much weight as well.
There are a lot of people that will suggest using the drysuit for buoyancy. In my opinion, that just increases the possibility of an air bubble moving around. Strictly speaking, you don't need air in the drysuit for any reason but to prevent squeeze and keep warm. If you're lacking confidence due to the amount of air in your drysuit, put less air in the drysuit and use your BCD for buoyancy control instead.
If you fall off the horse, get back on the saddle! You won't learn how to dive dry by diving wet.
Anyway, good luck and tell us how you're doing.