while I can imagine that self-medicating with your diagnoses is very tempting, it is also dangerous. Hydrocodone is a opiate, and it is addictive. Pain medication addictions are just as destructive and hard to treat as any other drug. Hence hydrocodone and other opiates are controlled substances that should only be taken under medical supervision. Abuse of these drugs, particularly when they are used with alcohol, is associated with significant health risks. You have enough issues to contend with having ADHD and bipolar disorder, so I would not recommend you add an addiction to the list of things that can negatively impact your life.
I know your medication options for bipolar disorder are often unattractive. Taking lithium or anticonvulsants creates side effects that many people dislike. Some people refuse to take medication to manage their symptoms because they love the highs of mania and hypomania. However, the risks of untreated bipolar disorder are significant. Untreated bipolar disorder is assoicated with elevated risk of suicide and other self-destructive behavior (such as risk-taking, impulsive spending and promiscuity during manic states). This disorder is too serious to try to manage on your own.
I would strongly recommend you get a referral to a psychiatrist who can help you. Under no circumstance should you continue to take opiates obtained from illegal sources (how do you know what is in that pill if you don't get it from the pharmacy?) There is also a book you may find helpful called An Unquiet Mind by Kay Redfield Jamison. Dr. Jamison is a renown professor of psychiatry at John's Hopkins who wrote this memoir about her struggles with bipolar disorder. There are also two websites you may find interesting to read about other people's struggles including http://www.bipolarhome.org/ and http://www.bipolarworld.net/ (though I can not vouch for the accuracy of any medical/psychological advice contained in these sites, so be critical of what you read there).
Disclaimer: This Medhelp post is written for informational purposes only. It is never intended to replace face-to-face psychological or medical care. This post is not intended to create a patient-clinician relationship, nor to give or rule-out a diagnosis.