@Stimfreak2234 it does sound like you have Bipolar as your doctors have said, and that it was triggered and/or worsened by the drugs. I have Bipolar 2 myself and the worst hypomanic episode I have ever had was also worsened significantly by antidepressants and DXM (I believe I was 16 at the time as well, same as you.)
Prozac and DXM are both known to worsen and/or trigger mania in Bipolar individuals with this theorized to be due to the serotonin reuptake inhibition caused by both. But there is no evidence that they can cause Bipolar in healthy individuals who are not at risk of developing bipolar. With a neurotypical individual, the mania would generally only be triggered by high doses and go away once the drug was out of their system and serotonin levels returned to baseline. You need to be at risk of disorders like bipolar or schizophrenia to develop them - though methamphetamine abuse can cause long-term psychosis that is somewhat similar in severe cases.
I want to emphasize that having Bipolar does not mean that you cannot lead a normal, functioning life. Plenty of successful people and celebrities suffer from Bipolar and other mental illnesses. This can range from ordinary people to famous scientists or actors/writers/musicians. Bipolar is actually exceedingly common in the music industry. Many famous people in history are also believed to have suffered from the disorder, such as Isaac Newton, Vincent Van Gogh, and Ludwig van Beethoven. I'm not saying that the lives of any of these people are what you will experience or what you should even aim for - as everyone is different and has different goals in life - but you can be extraordinarily successful with or without bipolar disorder.
Getting treatment is obviously important. Overmedication can be an issue and you should advocate for yourself and try to start with the milder meds like Lamictal before you jump straight to something like high-dose Lithium or antipsychotics that will have a heavy side effect profile. Just remember that when left unmedicated, the disorder will often worsen and mania can cause permanent brain damage over time. A good, very high-profile example of a bright individual with untreated severe bipolar (and possibly other mental illnesses) is Kanye West. It is pretty clear to everyone at this point that he has deteriorated significantly over the past two decades, with much of said deteroriation attributable to his untreated mental illness.
So my advice to you is this: Get some treatment. Therapy and light medication is a good start. Ensure that you maintain strong, healthy relationships with family and friends if you have a support system. Get into a sleep schedule. Consider getting into a routine of exercise, meditation, and maybe a healthy diet. And finally, lay off the drugs where possible.
DXM, SSRIs, stimulants (depending on the person, but generally recreational use should be avoided), PCP-derivatives, and alcohol are among the worst offenders for people with bipolar. Psychedelics really depend on the person. They moderate episodes for some and trigger them for others. Generally psychedelics and stimulants are more of an issue for those with type 1 Bipolar than type 2, but plenty with type 1 have no issue with these drugs and plenty of people with type 2 can have disastrous reactions.
Best of luck,
arrall