Withdrawal will not produce fever. Wow, that is an impressive quantity of drugs!. The black tar and the methamphetamine might not be exactly what you think and other agents in it certainly could have consequences. But by far the most likely is that the injection was not sterile and germs got into the system. There are a lot of possibilities here! Regular skin germs which can be introduced by technique and even occur with sterile solutions and sterile unopened syringes (injected through dirty skin) are the most common. They can cause local boils but can have infection anywhere hit by the circulatory system. Heart valves can be infected and this can be quite hard to diagnose. Other infections include but are not limited to hepatitis B and/or C, HIV, a lot of tropical diseases if someone connected to the injection was associated with areas outside of the US (malaria for example). Then there can be a reaction to what was in the injection. Black tar is quite gummy and can trigger immune responses. These would not be expected to last as long as the high in general with the materials producing both are cleared from the body in hours. Then, there can be total coincedences and infections/flu/illnesses occurring totally unrelated to drug use. happens.