Hunterdon County is rather strict compared to some other Counties on Drug/ CDS charges. However the Judge hearing the criminal cases is reasonable as are most of the prosecutors. From experience they will be more concerned with the endangering charge than the CDS. If this is your first offense you can likely avoid jail time based on the facts you present. The question is whether you can keep your record relatively clear and square the situation with DYFS. Even if this is not your first offense there are ways to avoid jail time. You do not indicate the degree of the drug (CDS) charge. I assume it is 3rd degree. You will be assigned a PD. A private lawyer can get into the case earlier and start laying groundwork for a positive outcome. But the PD will help you as well. Depending on the details of the case there may be a few defenses that need to be explored. Call for a phone consultation is you like.
Conspiracy to distribute cds and endangering the welfare of a child are serious charges that carry up to five years in prison upon conviction. Depending on your criminal history, a likely outcome could be anywhere from probation with no jail time conditioned on drug treatment, parenting classes and community service to jail time with probation or prison time. You need a lawyer. If you can find a way to borrow money to hire a private attorney, that would be best. Remember this is about you and your children and the rest of your life. A private attorney is more likely to invest the time in your case needed to find a resolution that you can live with. If not, you will get a public defender who will work for you but under the time constraints of their heavy caseload.
This answer does not create an attorney-client relationship and is based only on the limited information provided in the question.
The sentence you are facing will depend to a large degree upon your prior criminal record, if any. The steps you must take to have your children returned will also depend to a degree on whether you have any prior history with DYFS. You definitely need an attorney for the criminal charges, and I would advise that you try to hire an attorney who can also guide you through the DYFS steps. It is easier and more cost efficient if you can find an attorney who is familiar with both areas of law. If you absolutely cannot afford an attorney, apply for a public defender as soon as possible.