Welcome to Health Care Magic
Heroin is a drug of Opium group, it is highly addictive. You have been using this drug for about 19 years so if you will stop taking the drug suddenly without expert supervision there are chances of severe withdrawal. Withdrawal syndrome of heroin may usually present as mild flu like symptoms to irritability, restlessness
, anxiety, abdominal spasms, muscle soreness, lacrimation, slurred voice, tremors, headache, rhinitis
and some times with seizure also.
So in detoxification
centers when heroin de-addiction is done usually a drug that is similar in pharmacological action but less addictive than heroin is used for replacement. It not only prevent withdrawal syndrome but also help in maintaining the motivation. Then the drug is gradually tapered and ultimately individual becomes drug free.
is Buprenorphin and naloxone combination in fixed dose, buprenorphin is similar to heroin but less addictive (partial agonist) and naloxone is antagonist drug. The drug is given to prevent the withdrawal syndrome. But as you have mentioned that the drug made you sick, this happened probably because of improper dosing because equivalent doses are given, so that individual don't get sick.
For abdominal spasms, muscle soreness you can use any non-opioid analgesic
Percocet is not a good idea because it will just shift you from one drug to another.
Best in your case is visit a good Psychiatrist
and get your self admitted in some good rehabilitation
center for quick recovery.