There are options, but you must look at the situation honestly. On one hand you are using opioids intravenously- but you describe yourself as having a 'stable, loving environment.'
Every time you shoot up, you risk hypoxemia-- low blood oxygen level-- that could kill the fetus. The opioids themselves are not toxic, although as stated above, benzos ARE toxic to the fetus. You must get help-- significant help. If you do the right things, your doc will become your advocate.