Brand0n:well i was out yesterday and notice my air consumption is improving, with time i will be up to par, but one thing that makes me suck air like crazy is when i hit around 40 feet i cant seem to get streamline im pointing up with my head slitly and trying to swim around is much more difficult i belive i may be over weighted, but without this weight i cant get down this deep. soon as i hit 30-40 feet i sink like a rock and have trouble staying of the bottem.
spectrum makes some good points. At the end of your dive do a proper buoyancy check to see exactly how much weight you need. Let all the air out of your BC - make sure it's all out - and take in a normal breath. You should float at the surface at eye level. When you exhale, you'll sink. If you can do that, then you have the exact amount of weight you need.
To add to spectrum's remarks, try moving your tank a little higher on your BC. That will move some of the weight towards your head and allow you to be more horizontal.
Finally, expect to be a little overweighted at the beginning of the dive. You'll need to compensate for this by adding air to your BC for the first part of the dive and let out a little every few minutes as you breathe down your tank.
Hope this helps!