If you are given antibiotics to treat a STD, it is important that you take all of the drug prescribed to you, even if the symptoms go away. Also, do not take someone else's medication to treat your infection; it may make it more difficult to treat. Here are some specific STD treatments:
LDL and HDL are very different lipoproteins. LDL is generally fatty acid rich with cholesterol ester (CE) core. Its density is low because it carried a lot of traiglycerides (TG) and so floats. It has a specific apolipoprotein marker which tells the body which lipoprotein it is.
LDL means Low Density Lipoprotein which is as you say a type of bad cholesterol, the (calc) means it was calculated by a machine using a formula based on your own levels of cholesterol, triglycerides and HDL or Good cholesterol rather than being meassured directly.