Pennywise, a lot depends on the instructors you have access to. It sounds like what you need right now is not new stuff to learn, but improvement in the basic skills you've already been taught. A good peak performance buoyancy class could help, but not all of them are worth very much. You might actually get a lot more out of diving with an experienced mentor (again depending on the mentor!)
From Lodi, where do you normally dive? If it's Monterey, there are a lot of experienced Monterey divers on this board, and you could ask to hook up with one of them for a weekend, and see if they can help you sort out gear and weighting and so on.
From Lodi, where do you normally dive? If it's Monterey, there are a lot of experienced Monterey divers on this board, and you could ask to hook up with one of them for a weekend, and see if they can help you sort out gear and weighting and so on.