You are learning a lot of new skills in a new environment with lots of gear. Don't be so hard on yourself!
As others have said, it takes time to master these skills... give yourself that time. Remember learning to ride a bicycle? That took time didn't it? But before you knew it, you were riding along as if you'd done it your whole life!
1) In that much neoprene it is not uncommon to require that much weight to get neutrally bouyant. As has already been said, not all of it has to be around your waist. Options: ankle wts, tank wts, a steel tank. All of these distribute the wt along your body, which in turn will make it easier for you to maneuver.
2) Take control. People who are new to the sport tend to let the equipment get the upper hand. Remember, it's just gear... don't let IT be the master... YOU master IT! Relax. As using scuba gear becomes more familiar, your confidence will go up, and those "problems" will disappear.
3) When you become more comfortable in the water, you'll find that you can start shedding some weights. New divers tend to use a lot of air, and that makes you more bouyant. Later, as you become more experienced, you'll find yourself needing less lead to become neutrally bouyant... and off it will come.
4) Taking off/on the weightbelt while at the bottom. This can be done a couple of ways:
I (a) undo the belt. (b) maintaining a firm grip on the end in your right hand, pass the other (buckle) end behind your back so that BOTH ends are in your right hand. (c) pass the left back behnd you and return the buckle end to the front & do it up. The buckle should be in your left hand. *Check to make sure you have no hoses or other gear caught UNDER the belt.
II (a) Take off the belt. (b) Maintaining contact, open it & lie it on the bottom so that the inside of the belt is facing you and strap is in your right hand. (c) Keeping contact with the belt, lie down on it and roll over left side until the belt is lying over you. The buckle should be at your left hand. Just do it up. *Check to make sure you have no hoses or other gear caught UNDER the belt.
Voila!
The PRIMARY thing to remember when taking off/on ANYHING underwater, is to ALWAYS MAINTAIN A HOLD ON IT. With the wt belt, another thing to remember is that THE BUCKLE SHOULD ALWAYS BE IN YOUR LEFT HAND. (Right hand release.)
If you have any other questions, please feel free to email me.
Take care, eh?!
~SubMariner~